# CO2 revelations



## Georgiadawgger (Apr 23, 2004)

Good stuff Tom. 

I was wondering how well the little disk diffusers worked. I may have to try one someday.


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## Jason Baliban (Mar 3, 2005)

What questions are being addressed here?

Are you saying that dissolved CO2 is less "available" to weeds? Thus stating that CO2 that is not fully dissolved CO2 is actually more beneficial?

Wouldnt this make the PH/KH relationship even less reliable. These floating bubbles in the tank effect PH or do not effect PH?

I'm not sure what exaclty we are uncovering here? Are we talking about CO2 effeciency as far as administering or beneficial as far as plant usage?

Thanks

jB


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## Robert H (Apr 3, 2003)

I guess you have to go to his WEB site. I didn't understand 80% of what he wrote here, did you? I have so many tanks in my shop that I have the C02 connected to power heads that just blow it out into the water, into the path of a filter out take. According to what Tom has said here this is actually better than a reactor and I should be getting super growth and pearling????

Thats not the case at all for me. I only do this because it is a lot cheaper than setting up reactors, but I do not get tremendously fast growth or rapid pearling. These aren't display tanks and have no fish. In the past I have used ceramic disk diffusors, Eheims, and it was a total waist of time. It was much more difficult to reach 30ppm and hold it there consistently than when I used a reactor. Tom used to make reactors. I used to sell his reactors. Once you figured out how to put them together they worked great. In fact I think it was he and his reactor that converted me from the inefficient Eheim diffusor. Now we are taking a step back? I don't get it.


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## shalu (Jan 16, 2003)

Tom, apart from "pearling", have you compared actual plant growth in terms of inches/week?

In my non-CO2 tanks, I have been supplying AIR into the HOB filter via an air pump. The filter spits out a mist of tiny air bubble(a small percent of that is CO2, of course) in the output flow. I would see a lot of "pearling" on my plants, and I never thought it could be real pearling and assumed that those were tiny air bubbles collected under the leaves and formed bigger bubbles.


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## malkore (Nov 3, 2003)

shalu said:


> Tom, apart from "pearling", have you compared actual plant growth in terms of inches/week?
> 
> In my non-CO2 tanks, I have been supplying AIR into the HOB filter via an air pump. The filter spits out a mist of tiny air bubble(a small percent of that is CO2, of course) in the output flow. I would see a lot of "pearling" on my plants, and I never thought it could be real pearling and assumed that those were tiny air bubbles collected under the leaves and formed bigger bubbles.


You are increasing oxygen artificially by injecting air into the HOB...thus you reach O2 saturation more easily, so the plants pearl almost effortlessly.


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## Georgiadawgger (Apr 23, 2004)

shalu said:


> Tom, apart from "pearling", have you compared actual plant growth in terms of inches/week?
> 
> In my non-CO2 tanks, I have been supplying AIR into the HOB filter via an air pump. The filter spits out a mist of tiny air bubble(a small percent of that is CO2, of course) in the output flow. I would see a lot of "pearling" on my plants, and I never thought it could be real pearling and assumed that those were tiny air bubbles collected under the leaves and formed bigger bubbles.


That could be the case too...hummm

As far as the co2 gas being better in bubble form vs. dissolved in water, that is a puzzling aspect. Wouldnt submerged plants benefit better from the gas exchange in the medium they are growing in? 

One of the interesting things I've noticed about external reactor is the excess gas buildup inside that is part co2 part o2 that sucked in by the filter/pump via intake. I had this issue running my external reactor that was made from 1 1/2 inch tubing (15 inches long) attached to my 2224. Once I upgraded both reactor (to 2 inch diameter, same length) and attached it to my 2026, I never get a huge gas buildup inside the reactor. 

Two modifications I've made: 1. a venturi valve at the top of the reactor with an airline that goes into the tank. I got tired of flipping the reactor upside down every time I cleaned my filter (the air gap in the hoses surges into the reactor); which was also built to purge excess air from the reactor in the evening. 2. put the input from the filter on the top-side of the reactor rather than top-down...this swirling action seems to dissolve co2 quicker.


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## shalu (Jan 16, 2003)

If Tom's theory about CO2 bubble (100%) being far better than dissolved Co2(30ppm) is right, then perhaps indeed aeration alone helps quite a bit with plant growth. After all, air has 0.033% Co2 by volume, which converts to 502 ppm by weight, still far higher than our CO2 concentration in water.

When I started aerating my non-CO2 tanks, I was only thinking about keeping CO2 level at least at equilibrium level in water: about 2 ppm. Maybe I am getting the unexpected benefit of those tiny bubbles. By the way, don't try connecting those CO2 diffuser discs to air pumps. The higher pressure from air pump builds up and destroys the disc in a second. Wasted my $15 diffuser.


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## plantbrain (Dec 15, 2003)

Jason Baliban said:


> What questions are being addressed here?
> Are you saying that dissolved CO2 is less "available" to weeds? Thus stating that CO2 that is not fully dissolved CO2 is actually more beneficial?


I am suggesting in this particular case



> Wouldnt this make the PH/KH relationship even less reliable. These floating bubbles in the tank effect PH or do not effect PH?


Yes.



> I'm not sure what exaclty we are uncovering here? Are we talking about CO2 effeciency as far as administering or beneficial as far as plant usage?
> 
> Thanks
> 
> jB


I'm saying the delivery is the issue here and the form of the CO2(gas or dissolved in water).

Which do you think would improve growth faster?
1. Gas pure 100% CO2?
2. 30ppm is thick visicous water?

The concenration and the diffusion rate of gas is much higher on both counts.

pH/KH issue: if the bubbles are still gas and not yet dissolved(they can be asorbed by plants before hand or bubble out the top of the tank etc) then this will make the tank appear to have lower CO2 ppm wise based on the chart.

We recently added a venturi to a reactor design on a 180 gal tank here in SF, nothing was changed other than this loop. The result was a an increase in pearling by about 2-3 hours eariler. pH decline of 0.3.

This difference in growth is large enough to warrant serious consideration. It is significant, more so than little trace dosings, miracle joices and what have you.

Does not matter when you do a water change.
I have been using diffuser disc for some time on all but one of my personal tanks that have CO2 added.

Some minor changes like this have greatly improved the health. The reactors
are good if they produce a mist. 

This at first seemed counter productive, it wasted gas after enough of a CO2 bubble formed the last 1/2 of the day.

But that is when pearlign really kicked in.

So I added lots of CO2 right away to produce misting right as the lights came on and continued.

The results were the same as when I use the diffuser stone and current.

Placing the diffuser stones in the current, keeping them clean will great improve things if done properly.

I've use diffuser disc off and on over the last 10 or so years.

But now I fully understand the potential use of these as well as the venturi reactor and why both radically different methods work similarly.

Think about it like this, even at 3% CO2 in the air, plants grow faster in emergent set ups.

Adding 100% CO2 will improve plant growth terrestrially as well.
So the same should hold true for submersed growth also.

Robert makes a good point:


> According to what Tom has said here this is actually better than a reactor and I should be getting super growth and pearling????


Well a normal reactor, not with the venturi.



> Thats not the case at all for me. I only do this because it is a lot cheaper than setting up reactors, but I do not get tremendously fast growth or rapid pearling.


You need consistent small tiny bubbles and to move them through the plant beds as evenly as you can.



> These aren't display tanks and have no fish. In the past I have used ceramic disk diffusors, Eheims, and it was a total waist of time. It was much more difficult to reach 30ppm and hold it there consistently than when I used a reactor.


Yes, many felt this way but many here in SF also used them quite well(they killed their fish but that was due to a lack of a needle valve, those with the valves did very well).

Reflecting back and using them like the venturi reactor instead of passively increased the plant growth and measuring the CO2 was no longer even really needed in terms of pH/KH. Steve Dixton used his Ehiems very successfully this way, so has Jeff and other folks.



> Tom used to make reactors. I used to sell his reactors. Once you figured out how to put them together they worked great. In fact I think it was he and his reactor that converted me from the inefficient Eheim diffusor. Now we are taking a step back? I don't get it.


Actually, getting a handle on a few things, we might be able to target excellent CO2 levels with less issues to fish/higher CO2 for the plants, and easier methods to do it.

Even if the test are little off(which very often they are).

Regards, 
Tom Barr

www.BarrReport.com


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## plantbrain (Dec 15, 2003)

shalu said:


> If Tom's theory about CO2 bubble (100%) being far better than dissolved Co2(30ppm) is right, then perhaps indeed aeration alone helps quite a bit with plant growth. After all, air has 0.033% Co2 by volume, which converts to 502 ppm by weight, still far higher than our CO2 concentration in water.
> 
> When I started aerating my non-CO2 tanks, I was only thinking about keeping CO2 level at least at equilibrium level in water: about 2 ppm. Maybe I am getting the unexpected benefit of those tiny bubbles. By the way, don't try connecting those CO2 diffuser discs to air pumps. The higher pressure from air pump builds up and destroys the disc in a second. Wasted my $15 diffuser.


If you use pure O2 and regulator it works well

Is 0.033% going to grow plants better or is 100% going to grow plants better?
Both are gas phases.
30ppm will work mind you, and can do quite well.
But this is definitely better, which is the revelation part.

I'm talking every odd wimpy plant species you can think of.
Suddenly growing and pearling like no tomorrow with only this one change.


Aeration adds enough CO2 for marine plants BTW, I'd like to try a non CO2 aeration tank, but as Sha lu found out, the diffuser did not work well.

I'd like to get a compressed air tank instead of the pure O2 and see if this would do well for the non CO2 method..............ah that would be cool.

The key here is bubble size, it needs to be very fine.
I know folks have tried vigorously aerating and in certain part of the tank you can see good results from this, but at higher levels of finer aeration, I wonder if this could be improved.

If so, that would be a radical change, no CO2, no CO2 dosing , no CO2 fish kills and better growth than non CO2 etc.

Dissolving O2 is not the goal, getting the bubbles very small and onto the plant leaves is the goal.

Regards, 
Tom Barr

www.BarrReport.com


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## shalu (Jan 16, 2003)

I first did the aeration on my 10 gallon shrimp tank. I treat it like a low tech tank and dose it as such: very little, that is. My initial goal of aeration was two folds: 1) enough O2 at all times for sensitive shrimps. 2) some CO2 in water at all times during photoperiod. I don't like the large bubbles from the air stone directly, so I feed the air stone into the HOB filter intake. The bubbles were broken by filter impeller and lots of tiny bubbles were mixed in the filter output. I got exactly what I wanted, and then some. I got surprisingly fast growth from couple of weeds: najas and lagarasiphon madagascariensis. Granted, those are easy plants, but the growth rate was astonishing. I have to prune them every few days, not weeks. In the mean time, I see deficiencies developing in other plants(pale, smaller growth etc). Those same plants used to provide slow, but steady and lush growth. It is obvious now that I am really underdosing. What used to be enough is no longer enough.


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## Hypancistrus (Oct 28, 2004)

That could be one of the reasons Amano's tanks do so well... he uses CO2 "micro bubblers" as diffusers.

You can buy them for a _realistic_ price here --> http://www.aquabuys.com/miva/mercha...co2_diffuser&Category_Code=i3&Product_Count=1.


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## rrguymon (Jul 10, 2005)

plantbrain said:


> You can make a purge loop for external reactors by making a hole 1/2 down and running the air line back to the intake for the power head, caniter filter etc, this will not add bubbles but will reduce the gas build up inside the reactor.
> 
> Regards,
> Tom Barr
> ...


I am not sure I follow this. Unless you are saying you need two pumps. If run the gasses that are in the reactor back to the intake of my canister filter won't the gases just keep taking the scenic route through my filter to the reactor and back over and over again?

It would make more sense to me to run the gas over fill tube to a totally separate pump or power head. That would really get it out of the filter loop. It might even work if you just routed it down stream of the reactor in the output side of the canister. You might get a venurti effect that would draw it out or you might just pump the same water through the reactor over and over again.

Thanks

Rick


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## Tino (Jan 9, 2005)

Tom,
completely, wholeheartedly agree on the effectiveness of ceramic disc diffusers, had similar successful experience myself, and look at Amano and Oliver Knott's tanks - it was their #1 choise all along!


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## stcyrwm (Sep 1, 2005)

This is too cool. I've got a compressed air tank. What else would I need???? Something to regulate pressure but it would start lower than a CO2 tank so this could be much simpler and cheaper. Then feed it into diffuser by powerhead and we're off and running. Any thoughts? Refills by my own compressor or bring it to the gas station - lol...........

I'm going to try this tomorrow.........

Bill





plantbrain said:


> If you use pure O2 and regulator it works well
> 
> I'd like to get a compressed air tank instead of the pure O2 and see if this would do well for the non CO2 method..............ah that would be cool.
> 
> ...


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## jimmydrsv (Apr 8, 2005)

I think a few people are still confused about this idea. Here is what i thought about to better understood the idea.

It is how cells perform diffusion processes of waste and nutrients.

If you have a high concentration of something outside or inside the cell it will naturally want to balance out the concentration anyway it is allowed to.

Example:
If you ever got a sore throat, you might have heard someone tell you to gurgle saltwater. The high salt content of the water contrasts with the salinity in the bacteria cells in your throat creating a rapid diffusion process where water is sucked out of the cell until the salinity inside and out of the cells are the same. You end up with inploding bacteria cells with the overall effect of clearing up your throat. 

Reverse this idea:

Expose a saltwater fish with a certain salinity in its cells to pure 100% h2o and you end up exploding it's cells since they rapidly take in the h2o and the cell membranes break.


This idea as it pertains to co2 on leaves is like bloating up a plant cell with co2. If a plant had a prefered maitained co2 level, it will fight the concentration gradient by exporting co2 out of it's cells. At normal disolved levels it would be easier to fight the co2 coming in. With this process its like shoving food down its throat and waiting for the waste to come out the other side. :icon_bigg


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## plantbrain (Dec 15, 2003)

Hypancistrus said:


> That could be one of the reasons Amano's tanks do so well... he uses CO2 "micro bubblers" as diffusers.
> 
> You can buy them for a _realistic_ price here --> http://www.aquabuys.com/miva/mercha...co2_diffuser&Category_Code=i3&Product_Count=1.


Yep and often has suspiciously low CO2 readings.
If you place current near these and blast the gas all over, you will see better growth wherever you blast the bubbles.

Regards, 
Tom Barr


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## plantbrain (Dec 15, 2003)

Tino said:


> Tom,
> completely, wholeheartedly agree on the effectiveness of ceramic disc diffusers, had similar successful experience myself, and look at Amano and Oliver Knott's tanks - it was their #1 choise all along!


True but that damn Scottish engineering in me........actually Dupla stuff, I've used diffusers very well in the past, but now I know why they and the DIY Venturi did equally so well.

You do not need a diffuser stone to do this, but they are smaller
They were also used to rule out excess O2 bubbles. 

Regards, 
Tom Barr


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## [RK] (Aug 11, 2005)

I use to shoot the bubbles all over my tank too. But the tank just looked too weird with tiny bubbles everywhere, so i position the reactor in the back corner :S


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## Robert H (Apr 3, 2003)

> You need consistent small tiny bubbles and to move them through the plant beds as evenly as you can.


Are you talking about at the base of the plant? What about low growing plants?



> You need consistent small tiny bubbles and to move them through the plant beds as evenly as you can.


But that is the main problem with a diffusor. The bubbles never stay tiny enough. The disk gets dirty, covered in algae and the bubbles get bigger and bigger. And no matter how tiny they are, a percentage of them still rise all the way up to the water surface and disapate.



> That could be one of the reasons Amano's tanks do so well... he uses CO2 "micro bubblers" as diffusers.


Yes, and there are cheap knock offs of Amanos diffusor made in China which are sold on the internet, even by one of the sponsors here I believe, no better no worse than Amanos, just a lot cheaper, and I have read numerous complaints in the forums about how difficult it is to keep a constant level of C02 using it. Diffusors are air stones. Big deal.




> Think about it like this, even at 3% CO2 in the air, plants grow faster in emergent set ups.


Plants in the atmosphere do not have the Prandtl boundary that surrounds aquatic plant leaves. This is a layer of still water through which gases and nutrients must diffuse to reach the plant leaf. It is about 0.5 mm thick or ten times thicker than the layer surrounding airborn plants. This is why much higher levels of C02 are required underwater than above water. I am sure you know this Tom. When a C02 bubble comes in direct contact with a plant leaf, does it break thru that barrier faster than C02 that is absorbed in the water? Perhaps it does, but it can not be constant.

How on earth can you "blow" Co2 bubbles to come in contact with every plant in the tank? It is impossible. Is it worth cranking the gas up to such a level to benefit the few plants it comes in contact with while a large percentage simply dissapates at the water surface, or is it more efficient to pump C02 enriched water into the aquarium which builds up the level through out the tank to benefit all the plants and keeps the level at a steady consistent level?



> Yes, many felt this way but many here in SF also used them quite well(they killed their fish but that was due to a lack of a needle valve, those with the valves did very well).


Well thats because one of your "members" still sells the bloody thing. I threw out his regulator and diffusor years ago, and have never looked back.

I am not trying to pick a fight, but I like to to read consistent information from a authoritive source, and when that source starts taking an about face, it makes me doubt the authority of that source, or to make it less personal, because I do not mean this as a personal attack, it just plain raises doubts for me.


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## plantbrain (Dec 15, 2003)

Robert H said:


> Are you talking about at the base of the plant? What about low growing plants?


The reactor venturi spreads to mist downward.
The flow is important!
Shooting the flow along the bottom rear is a good plan, depends a little on the scape.

>But that is the main problem with a diffusor. The bubbles never stay tiny >enough. The disk gets dirty, covered in algae and the bubbles get bigger >and bigger. And no matter how tiny they are, a percentage of them still rise >all the way up to the water surface and disapate.

Yep, there is variation, but keeping them clean is not too much work, I do it once a month. Some place gravel on them to prevent algae/biofilm.

The reactor method produces a better consistency and production rate I think.

"Yes, and there are cheap knock offs of Amanos diffusor made in China which are sold on the internet, even by one of the sponsors here I believe, no better no worse than Amanos, just a lot cheaper, and I have read numerous complaints in the forums about how difficult it is to keep a constant level of C02 using it. Diffusors are air stones. Big deal."

Yep, I've tried both now. I think it does take more skill to use the stones. 
I've done well with them both.
So have a number of folks here locally and in Asia.
Those that are not careful kill their fish!

There is no perfect CO2 method really.

"Plants in the atmosphere do not have the Prandtl boundary that surrounds aquatic plant leaves. This is a layer of still water through which gases and nutrients must diffuse to reach the plant leaf. It is about 0.5 mm thick or ten times thicker than the layer surrounding airborn plants. This is why much higher levels of C02 are required underwater than above water. I am sure you know this Tom. When a C02 bubble comes in direct contact with a plant leaf, does it break thru that barrier faster than C02 that is absorbed in the water? Perhaps it does, but it can not be constant."

Yep.
I am not sure how this affect relates, but I do know the growth rates and the DO levels are there.

That is something I know I can see and know what it looks like as well as measure.

"How on earth can you "blow" Co2 bubbles to come in contact with every plant in the tank? It is impossible. Is it worth cranking the gas up to such a level to benefit the few plants it comes in contact with while a large percentage simply dissapates at the water surface, or is it more efficient to pump C02 enriched water into the aquarium which builds up the level through out the tank to benefit all the plants and keeps the level at a steady consistent level?"

If you inject the mist along the rear bottom and blow the CO2 into the plant bed, the mist rises up through the plant's leaves, most are hit, you only need some of the entire surface area to be hit per leaf/plant etc.

Once inside the leaf, the CO2 can disperse.

"Well thats because one of your "members" still sells the bloody thing. I threw out his regulator and diffusor years ago, and have never looked back."

Huh?
Dave G?
He's not my member. 
The Ehiems had a check valve issue and some other issues, for the 100 gal, you needed 2 of them and a needle valve. I know more today and could have solved it either way today.



> I am not trying to pick a fight, but I like to to read consistent information from a authoritive source, and when that source starts taking an about face, it makes me doubt the authority of that source, or to make it less personal, because I do not mean this as a personal attack, it just plain raises doubts for me.


Well, we often learn new things and taking a new look when an observation suggest something is not a bad thing.

I learn and improve as well.

The about face is not really that except in terms of efficenecy, it's one based on delivery, getting the most CO2 to the plant.

I and everyone else focused on measurement of the dissolved CO2/DO, I broke the ranks with this here and considered them thar tiny bubbles. I did this with PO4 as well, and cables and yada yada.............

30ppm liquid vs 99.97%+ gas is a lot, and the results from the test I did showed this. 

I was not looking for this, it just happened(same with PO4).
But when it does occur, I consider why and then try to isolate it.
I was floored and went back and made some changes to rule the obvious things out.

I've changed the NO3/PO4 dosing routines a fair amount in the last 10 years also. Adding 2-3x as much now. 

I'm as surprised as you are actually.

I'm not sure why I nor other folks put it together sooner.
Many have obsevred their plants doing very well near the CO2 reactor outflows and disc.

Even if they good ppm on CO2, they still have better growth next to the reactor/disc.

I just never thought about 100% pure CO2 gas vs 30ppm pure CO2 in water.

I do not think anyone else did either. I am not sure why. Seems like a good question too. When I suggested it, folks went *"Doh!"*

The research suggested 30ppm was the max, this seemed to agree well, and it was better than the 10-15ppm recommendations that I broke ranks with a long time ago.

I just did what makes the plants grow better and then go back and see what conclusions I can draw from them.

The research has not investigated micro bubbles vs dissolved ppm in the water, but I already know based on diffusion rates of gases vs liquids and the DO/pearling effects that it's a big deal.

Everything looks like Riccia => R wallichii, Tonia, Red Cabomba about any stem plant. Not just for as few hours, most all day.

It's crazy looking.
I don't get this type of pearling even after a cool water change and good CO2 etc and I know what intense pearling appears like.

With some flow changes, most folks can amplify their CO2 this way, but they do need to be careful not to add too much CO2 and kill their fish/shrimp.

Regards, 
Tom Barr

www.BarrReport.com


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## Robert H (Apr 3, 2003)

He is your fellow SF club member. What I do remember is in what 1999 or 2000 when you came to my house to look at my tank and the first thing you said to me was get rid of that diffusor! You told me they were unreliable and unstable. You remember?

I think you are just trying to revive Gombergs business! :wink: At least it gives him something to talk about on APD. Cleaning once every five years...<smirk> yeah right.



> If you inject the mist along the rear bottom and blow the CO2 into the plant bed, the mist rises up through the plant's leaves, most are hit, you only need some of the entire surface area to be hit per leaf/plant etc.



Here is the problem with that. If you have a thick, tall jungle, that might work, but if you have any kind of an aquascape, you have open areas between plants as well as the foreground. Many aquascapes also keep the plants no taller than the mid level. If you are using a diffusor and you put it real low to the substrate in the middle of plants, it is in a much more vulnerable place to get covered with free floating matter from dissolved leaves and have algae and sedimant settle on it. This kind of throws out Gombergs claim of cleaning his disk once every five years. If you are going to set a powerhead or pump to blow it out, you can not have a pump too close to the gravel or it will suck up the gravel and debrie and get constantly clogged. So then your alternative is to set the pump and diffusor mid level between the gravel and the water surface. The outflow of my filters does not reach the bottom of my tank, and a really strong current will interfere with the plants...bending over stems, moving plants to where I do not want them.


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## Tino (Jan 9, 2005)

Robert H said:


> Here is the problem with that. If you have a thick, tall jungle, that might work, but if you have any kind of an aquascape, you have open areas between plants as well as the foreground. Many aquascapes also keep the plants no taller than the mid level. If you are using a diffusor and you put it real low to the substrate in the middle of plants, it is in a much more vulnerable place to get covered with free floating matter from dissolved leaves and have algae and sedimant settle on it. This kind of throws out Gombergs claim of cleaning his disk once every five years. If you are going to set a powerhead or pump to blow it out, you can not have a pump too close to the gravel or it will suck up the gravel and debrie and get constantly clogged. So then your alternative is to set the pump and diffusor mid level between the gravel and the water surface. The outflow of my filters does not reach the bottom of my tank, and a really strong current will interfere with the plants...bending over stems, moving plants to where I do not want them.


 You don't have to set up a pump to specifically disperse the mist. Provided you have sufficient circulation in the tank the mist will get dispersed no matter what IME. Regular routine maintenance of the disc will insure its long life.
The main point here is the efficiency of CO2 utilization through injecting directly into tank with a diffuser (even though CO2 reading may appear low) as opposed to reactor premixed form with higher readings.


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## brad (Aug 11, 2005)

Robert H said:


> Here is the problem with that. If you have a thick, tall jungle, that might work, but if you have any kind of an aquascape, you have open areas between plants as well as the foreground. Many aquascapes also keep the plants no taller than the mid level. If you are using a diffusor and you put it real low to the substrate in the middle of plants, it is in a much more vulnerable place to get covered with free floating matter from dissolved leaves and have algae and sedimant settle on it.


So maybe this isn`t the best way for everyone. The way co2 isn`t for everyone. High light.......Maybe what Tom is saying is that this provides better co2 concentrations to the plants. If your particular aquascape (or budget judging by the price of the disks) doesn`t allow for it, use the reactor. For those tanks that can do it this way, it may be a method worth trying.


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## Oqsy (Jul 3, 2004)

i just finished altering my CO2 rig to try tom's suggestion for a co2 "mist". I was already using a profile powerhead with a gravel vac for an internal hoft. style reactor. I moved the co2 input to the venturi airline-in on the powerhead, and just attached a small length of clear hose with holes punched in it to diffuse the flow a bit, giving me a half-jet, half-spraybar type outflow of water with pure co2 "mist" that's been chopped up in the powerhead impeller. i'm getting the tiny bubbles floating all around the tank, and going to continue with EI. I'll post back with my results.

picture attached for those interested in my UGLY co2 jet thingy. if it doesn't work very well, I can always go back to my old reactor, which seemed to be doing *ok*. thanks for the suggestion, tom

Oqsy


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## baj (Sep 16, 2004)

Tom, interesting idea and it does have a logical thought leading up to it, I am inclined to agree with jimmydrsv that if it works better it must be due to the concentration gradient at the leaf itself. I am trying it out using diy co2 and powerhead driven reactors. I attached the powerheads nozzle with tubing into the end of a gravel-vac and co2 fed through a hole drilled about an inch down from the top of the gravel-vac. By carefully selecting the length of the gravel-vac and the angle of placement, I am able to keep all the big bubbles confined inside while the jet from the powerhead pushes out a constant stream of fine bubbles. I am using two of them and get pretty good coverage on the entire tank which has the footprint of a standard 10g. The powerheads are also pretty close to the bottom of the tank, about 6" from the bottom, by using long enough hoses to connect the powerhead nozzle to the gravel-vac I can manoeuvre the jet stream.
However, the true metric will be plant growth and its too early for me to conclude anything. Also, since I am not running a control tank, my results will be subjective and speculative. Just from the bubbles on the plant leaves I cant tell. Its tough to seperate cause and effect that way, the co2 bubbles attach to the leaves and I cant tell if its really pearling . This has been on now since friday and fish/shrimps are doing fine.


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## timr (Mar 23, 2005)

I suppose this is good if you want a plant farm, or you must keep those tough to grow plants. but my tank requires enough pruning as it is. i know i don't have the most demanding plants, but i've had great success with a lot of different plants. i don't even know what my co2 level is, and all i dose regularly is trace and K (every other day). Iron once or twice a week, and some calcium and magnesium at w/c (about every 2 weeks). 

I don't think this is a suggestion for everyone. Not everyone will like the bubbles, not everyone will appreciate the growth (count me in on that one). But if you are trying to grow those not-so-easy-to-grow plants, this might do the trick.


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## shalu (Jan 16, 2003)

heck, if one does not want the extra maintanance, a non CO2 tank is perfect then. But that's not the point of the thread :icon_bigg


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## jhoetzl (Feb 7, 2005)

Hmmm, me thinks Tom is trying his idea on the open market. The Red Sea CO2 system uses a very small powerhead to create a fine mist of CO2 bubbles.

"Unique diffuser pump with CO2 venturi injector
* Injects micro bubbles from bottom of aquarium
* Optimum diffusion of generated CO2
* Enables lower CO2 diffusion rate at night "

Now, the question, do I try it out...I am currently using a hof' style reactor, and never really see pearling yet get excellent growth with next to no algae. But if there is more growth to be had, I'd love to see it. Hmmm...I do have another outlet on my manifold...hmmmmmm


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## Momotaro (Feb 21, 2003)

Joe, if what you are doing works...leave it alone. These things can be such a fine balance. Nothing worse than having to undo a mess created by experimenting. Been there! I remember working to clear up a GSA mess I created by experimenting with a new fertilizing regime. Jay laughed, and said you have something that worked why would you screw with it?

Try it on another set up!

BTW, it does sound a lot like the Red Sea unit.

Mike


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## albinooscar (Jan 25, 2005)

I guess my only questions are:

How can you be sure that there really is pearling and not just the tiny bubbles merging to create bigger bubbles?

Have you or are you going to test the gas contained in these pearl bubbles?
Maybe it's just the CO2 mist collecting?

I understand that you claim to have better growth but I think that there are things that still need to be looked at and proven.

Ron


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## jhoetzl (Feb 7, 2005)

Momotaro said:


> Try it on another set up!


OK, in my 15g DP tank I have a ladder being feed via pressurized. I have a small powerhead sitting on the shelf, so I might switch the ladder to that. I am not too bother by the status of that tank, but it does do well as is, but I am a tinkerer...


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## plantbrain (Dec 15, 2003)

Simple, that is what the Dissolved Oxygen test is for, that way you can measure what the O2 production rate *is*.

Well, provided you have such a device or a test kit for DO. 

Regards, 
Tom Barr

www.BarrReport.com


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## unirdna (Jan 22, 2004)

Interesting experiment. I'm always in favor of challenging the dogma. But, there is a huge snag in my understanding of how this works. Specifically relating to my understanding of how CO2 dissolves in water. 

My own experiment: Aim my spray bar downward and bubble CO2 through the airline to the bottom of my aquarium 20 inches high. The bubble of CO2 dramatically reduces size and speed (rising to the top, against the current of the spraybar) in less than one second (it is eventually blown out of the current and slowly rises to the top of the tank). The diameter of the bubble seems to reduce in size from 4mm to approximately 1mm. Using the volume equation for a sphere (V = 4/3 • p • r³), one can quickly calculate that this would be a 94% reduction in volume (15/16). This doesn't even take water pressure into consideration - which, of course, would make the percentage even higher.

If you are unable to perform this experiment, or question the conditions in which mine was performed, try this... If you are running an inline reactor, open your needle valve wide open on the CO2, allowing your reactor to fill up to 1/4 or so CO2. Then, see how fast that stuff dissolves into solution. Seconds! And what's left? A small quantity of seemingly "stubborn" CO2 bouncing around in the reactor? More likely some other gas that does not dissolve so easily. Why would 95-99% of the CO2 dissolve in seconds, and 1-5% "decide" to not dissolve? 

It is this (non-CO2 gas) that I think you are fighting so hard to disperse about your tank. - whether it be via your venturi method or the diffuser/water-movement method. In short, I would surmise that the reason you are seeing this pearling would be the result of oxygen super-satruation (as O2 is likely that "hard-to-dissolve gas that is being blown around the tank).

Until a concise, scientific explanation can be offered as to why CO2 dissolves so rapidly, yet can remain as small undissolved bubbles for lengthy periods of time under turbulent conditions, the likely conclusion is that these bubbles of gas are not CO2.


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## plantbrain (Dec 15, 2003)

Hi,




> My own experiment: Aim my spray bar downward and bubble CO2 through the airline to the bottom of my aquarium 20 inches high. The bubble of CO2 dramatically reduces size and speed (rising to the top, against the current of the spraybar) in less than one second (it is eventually blown out of the current and slowly rises to the top of the tank). The diameter of the bubble seems to reduce in size from 4mm to approximately 1mm. Using the volume equation for a sphere (V = 4/3 • p • r³), one can quickly calculate that this would be a 94% reduction in volume (15/16). This doesn't even take water pressure into consideration - which, of course, would make the percentage even higher.



The dissolving rate decreases as we over saturate the water with CO2.
This is why we have gas build up in reactors (and some degassing of the O2, but disc and airstones do not have this issue!).
The first hour, the bubbles are mostly dissolved, the last few hours, they are not.

The change in ppm of CO2 in the water affects the CO2 solubility.
It becomes harder and harder to add more beyond saturation.
While I say this, I do not know "how hard" but it seems to be relevant and worth addressing. 

The other issue one of surface/volume area. The surface volume area is much greater with a smaller bubble, hence faster dissolving and thus faster response to dissolving the CO2 when dosing gas CO2.

Once the CO2 ppm is high, say 20-30ppm, then the bubbbles will presist much longer(basically the reactor/disc etc are becoming more ineffecicent once you reach higher CO2 levels).



> If you are unable to perform this experiment, or question the conditions in which mine was performed, try this... If you are running an inline reactor, open your needle valve wide open on the CO2, allowing your reactor to fill up to 1/4 or so CO2. Then, see how fast that stuff dissolves into solution. Seconds! And what's left? A small quantity of seemingly "stubborn" CO2 bouncing around in the reactor? More likely some other gas that does not dissolve so easily. Why would 95-99% of the CO2 dissolve in seconds, and 1-5% "decide" to not dissolve?


This idea was addressed by using the disc and then see my comments above, also, you can try adding the CO2 and ourging the gas out later in the day after a good CO2 has built up, when the water is poor in CO2 or near ambient, see how long it takes vs later in the day.

I think you'll see a marked difference.

The CO2 ppm is not static, it does change, making this a cal math issue.



> It is this (non-CO2 gas) that I think you are fighting so hard to disperse about your tank. - whether it be via your venturi method or the diffuser/water-movement method. In short, I would surmise that the reason you are seeing this pearling would be the result of oxygen super-satruation (as O2 is likely that "hard-to-dissolve gas that is being blown around the tank).


I addressed this, simply.

I used a DO meter, this measures O2 accurately.
the only way to add more than 100% ambient levels is through plant production.

The other issue, the gas that will be in above stauration levels are going to be only O2 and CO2, eg N2, He, Ar etc will not be added from other sources(except as very small contaiments).



> Until a concise, scientific explanation can be offered as to why CO2 dissolves so rapidly, yet can remain as small undissolved bubbles for lengthy periods of time under turbulent conditions, the likely conclusion is that these bubbles of gas are not CO2.


A couple of folks said that, but given the purity of the CO2(99.97% or so based on the test done at the place I get my gas from), the bubbles would need to dissolve much smaller, plus for the above reasons, such as time of day and rate of dissolving etc, it depends on when you make that observation. Surface tension may play a role when they become very small also.

I too observe the same things as you do, but I begin to see pearling on plants asap, then I see more and more bubbles later not being dissolved and I see higher DO levels with this method.

Something is making the plants produce more O2 thus grow faster.
The main cause appears only to be the CO2 delivery method.

The tank has been cranking and producing much higher O2 levels over two weeks now. 
Regards, 
Tom Barr


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## jkolb (Mar 30, 2005)

Just a note. There will be diffusion into the bubble also, correct? So a large bubble of 99.97% CO2 could quickly become a small bubble of O2 as CO2 diffuses out and O2 diffuses in. 

Interesting reading. roud:


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## Oqsy (Jul 3, 2004)

alright, I've been running my setup with a spray of bubbles (slightly modified from pic earlier in thread, now about 26" of hose with holes every inch to two inches running across the bottom of the tank) for about 4-5 days now. I can say without a doubt that growth HAS increased, algae HAS subsided, and pearling HAS increased. How do I know that it's O2 bubbles on the plants, and not CO2? I don't *know* by any means other than the fact that in the morning, the plants have no bubbles under the leaves(co2 and new spraybar contraption stay on 24-7), but by about 6:30-7pm, every leaf in the tank (hydrocotyle, mosses, hygro, ludwigias, micranthemoides, bacopa, lysimachia, crypts, and marselia) is surrounded by bubbles, and the tank looks like an upsidedown rain shower, with bubbles shooting toward the surface. If it were CO2 bubbles, they would peak in the early AM hours before the lights came on and the plants started photosynthesis. But since they're showing up late in the day after the lights have been burning and the plants are revved up, it must be O2 bubbles. 

Another hint that it is pealing, and not just CO2 oversaturation is the improvement in growth, and the fastest recession of dust algae I've ever seen. I didn't clean the glass since my last water change, and the dust just went away by yesterday morning. My wife (who is no big fan of my tanks) has commented on how much *cleaner* the tank looks the last few days, and I have to say that with no other changes in my dosing, photoperiod or intensity, water paramters, temperature, or bioload, the change in CO2 delivery method is the best explanation. 

For those that don't believe it would work, you're certainly welcome to do things how you want. For those that are happy with their current setup, the same applies, but for those of you that are curious enough and have enough time to slip a disc on an airline, or a hose on a powerhead with venturi CO2 input, then give it a shot and see if it doesn't improve your growth, pealing, and decrease the amount of algae in your tank. If it doesn't work, you're out maybe 10 minutes of work (more likely 2) and $2-4 max. Much cheaper than the snake oil remedies for algaes, cycling, etc. that most of us tried early on in the hobby. 
I don't know the diameter of the bubbles of mist that Tom is using, but mine are under 1mm in diameter for the most part, and churn around the tank several times before disappearing. I've watched the surface of the water, and with the orientation of my spraybar, none of the bubbles can reach the surface. All are blown back to the front of the tank and swirled down to the substrate and swirl back up from the CO2 spraybar to the back and around again. Basically, circulation in the tank goes from the bottom rear, top rear, top front, bottom front, bottom rear again. I am out of KH test right now, so i don't know what my CO2 concentration is, but it can't be much more than it was before because my bubble rate hasn't changed a bit. I'll post photos of the new rig, pearling, and new growth tonight. 

thanks tom!

Oqsy


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## jimmydrsv (Apr 8, 2005)

All you ppm followers ask yourself this, are you trying to get co2 in the water or into your plants?

I think the easiest test for this is the intake of other nutrients in comparison to the ppm method and the micro bubble method.


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## plantbrain (Dec 15, 2003)

jkolb said:


> Just a note. There will be diffusion into the bubble also, correct? So a large bubble of 99.97% CO2 could quickly become a small bubble of O2 as CO2 diffuses out and O2 diffuses in.
> 
> Interesting reading. roud:


So how do explain the higher growth rates and O2 levels with each different method?

Regards, 
Tom Barr


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## plantbrain (Dec 15, 2003)

Oqsy said:


> I can say without a doubt that growth HAS increased, algae HAS subsided, and pearling HAS increased. My wife (who is no big fan of my tanks) has commented on how much *cleaner* the tank looks the last few days, and I have to say that with no other changes in my dosing, photoperiod or intensity, water paramters, temperature, or bioload, the change in CO2 delivery method is the best explanation.
> 
> For those that don't believe it would work, you're certainly welcome to do things how you want. For those that are happy with their current setup, the same applies, but for those of you that are curious enough and have enough time to slip a disc on an airline, or a hose on a powerhead with venturi CO2 input, then give it a shot and see if it doesn't improve your growth, pealing, and decrease the amount of algae in your tank. If it doesn't work, you're out maybe 10 minutes of work (more likely 2) and $2-4 max. Much cheaper than the snake oil remedies for algaes, cycling, etc. that most of us tried early on in the hobby.
> I don't know the diameter of the bubbles of mist that Tom is using, but mine are under 1mm in diameter for the most part, and churn around the tank several times before disappearing. I've watched the surface of the water, and with the orientation of my spraybar, none of the bubbles can reach the surface. All are blown back to the front of the tank and swirled down to the substrate and swirl back up from the CO2 spraybar to the back and around again. Basically, circulation in the tank goes from the bottom rear, top rear, top front, bottom front, bottom rear again. I am out of KH test right now, so i don't know what my CO2 concentration is, but it can't be much more than it was before because my bubble rate hasn't changed a bit. I'll post photos of the new rig, pearling, and new growth tonight.
> ...


Well there you go, arguing for or against it does not show you that it worked.
You must actually try it. Some things are not worth the gain, improving CO2 is a good thing.

I did not why algae did not grow when we first started adding PO4, but we did know right away I was on to something and it worked.

You'd figure after all the things I have gotten right over the years and very few wrong, folks would try it.

The results I'll let those that do tell their stories.
So far I've had 5 folks claim the same observations I've stated in the orginal premise.

I've seen it personally.

So........naysayers........how do you account for the added growth? It's not a mild growth spurt either and it does not decline over time(at least for the last 2 weeks)? The DO meter is not broke.

Carbon from the CO2 is 40-50% of the plant biomass.
I've suggested some plausible ideas of why the observation occurs.
Now if you test this, then you'll know and wonder the same thing, as well as have dramtic improvements in the appearance and growth.
Why is occurs is somewhat debateable at this point, but it's not boding well for other gases and the observation-correlation. 

Now if CO2 addressed, then nutrients are very easy, and light is easy also.
Then you have less issues, and a more robust method and stable tank.

Blah............who wants that?

Regards, 
Tom Barr

www.BarrReport.com


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## plantbrain (Dec 15, 2003)

jimmydrsv said:


> All you ppm followers ask yourself this, are you trying to get co2 in the water or into your plants?
> 
> I think the easiest test for this is the intake of other nutrients in comparison to the ppm method and the micro bubble method.



I was considering redoing the EI for this method, but the EI was developed against a very similar thing, the venturi reactor, this goes a little better than that though.

NO3, I have a kit that measures to 0.01ppm accuracy so I can give you an idea, but as plant biomass increases, so does uptake, so for comparison purposes, it needs to be an average. It's like hitting a moving target.
If tyou do the test over a quick time frame, say one day then try the other method and then back again, you might get something worthwhile test wise.

PO4/NO3 test kits introduce their own errors. Especially the cheapy ones.
O2 measurement is a better overall level of growth and the accepted measurement for submersed growth studies.

Terst kits for DO run 8-20$ or so and some are more etc, meters run 200$ or so and higher.

I have considered the increase uptake issue using this CO2 method with respect to other nutrients.

It's more work and I will not have time for awhile to really make sure the levels are a fair comparison.

I suspect perhaps 10-25% more uptake though.
But, that is merely a guess.

Regards, 
Tom Barr


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## glass-gardens.com (Apr 14, 2004)

so when are ya going to get around to posting a photo of the thing for us folk who don't visualize well?


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## unirdna (Jan 22, 2004)

plantbrain said:


> So far I've had 5 folks claim the same observations I've stated in the orginal premise.
> 
> I've seen it personally.
> 
> So........naysayers........how do you account for the added growth? It's not a mild growth spurt either and it does not decline over time(at least for the last 2 weeks)? The DO meter is not broke.





plantbrain said:


> So how do explain the higher growth rates and O2 levels with each different method?





jimmydrsv said:


> All you ppm followers ask yourself this, are you trying to get co2 in the water or into your plants?
> 
> 
> 
> ...


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## glass-gardens.com (Apr 14, 2004)

Right now why isn't as important to me as seeing the beast so I can take it and run with it


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## jkolb (Mar 30, 2005)

plantbrain said:


> So how do explain the higher growth rates and O2 levels with each different method?
> 
> Regards,
> Tom Barr


Not arguing at all. It's just a comment on the observations that the CO2 bubbles rapidly decrease in size at first, and then, at a much smaller size -but much larger than the 0.03% impurities could account for- seem to persist. If O2 was at saturation, you would expect some amount of diffusion into the bubble, which might explain why the bubble could stick around. Higher growth rates -> more DO -> more persistent bubbles due to diffusion of O2 in. The CO2 is still getting out.


I've got a Seio Superflow pump that should be perfect for the job. I'm anxious to give it a try.


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## Bert H (Dec 15, 2003)

> Right now why isn't as important to me as seeing the beast so I can take it and run with it


 Ditto for me as well! My engineering and visualization skills are non-existent, so I need a 'place A into slot in B' type of show and tell. Looking forward to some pics. roud:


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## scolley (Apr 4, 2004)

Bert H said:


> Ditto for me as well! My engineering and visualization skills are non-existent, so I need a 'place A into slot in B' type of show and tell. Looking forward to some pics. roud:


Also the same for an inline setup would be much appreciated.


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## Hypancistrus (Oct 28, 2004)

Do you mean, you need to see what a diffuser disk looks like set up, or you want to see pics as proof that it works?

If it's the former, you can see a ton of them in Marc's ADA gallery photo post.

For example, in the picture below, the glass diffuser disc is located at the left. It's an ADA "Pollen Glass Beetle Series" diffuser and they cost between $80 - $116 from ADG in the USA. The ADA technique is to run it only during lights on, and run an airstone on an airpump at lights off.










As you can see all the tanks do extremely well, but since they don't use "reactors," there aren't any such pics available for comparison. Personally, I'd like to see a test performed with two identical tanks with exactly the same conditions but one with a diffuser disc and one with a "reactor."


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## scolley (Apr 4, 2004)

I don't think the questions were about ADA diffusers. I think the questions were about pictures of Tom's reactor. Those pics I know (as a member) are available on Tom's forum - they've been there for a while.

My question is about more visual detail about how to rig an in-line reactor. I've read what's posted here, and I do not get it.

Originally Posted by plantbrain

_You can make a purge loop for external reactors by making a hole 1/2 down and running the air line back to the intake for the power head, caniter filter etc, this will not add bubbles but will reduce the gas build up inside the reactor.

Regards,
Tom Barr_​

Huh? Maybe a visual would help. Maybe a better description...

On Tom's site he indicated quite a while ago that such pictures/diagrams would be available in a couple of months, but I can't find it. I'd love to see it. Or mabye it will show up on Tom's forum.


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## Hypancistrus (Oct 28, 2004)

scolley said:


> I don't think the questions were about ADA diffusers. I think the questions were about pictures of Tom's reactor. Those pics I know (as a member) are available on Tom's forum - they've been there for a while.
> 
> My question is about more visual detail about how to rig an in-line reactor. I've read what's posted here, and I do not get it.


OK, now I'm seriously confused by what you mean. I thought the whole point of this thread is that diffuser discs work better than reactors? Am I missing something here? :icon_conf


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## duck (Apr 22, 2004)

Reading this thread with interest and just thought about the reactor that i'm running seems a little different than the one's i see around the place.
My plant's pearl every day,I leave my CO2 24/7 I have increased my CO2 but i run a air pump &stone 1 hour after light's out then 1 hour before light's on it cut's out(due to loss of fish) and my plant growth is noticeable better since the increase.

Here's a pic of my reactor If you notice the output line's are both on the bottom on the reactor, on the left bottom you will see tubing that the CO2 goes in and the CO2 up the top spinning around should i say water.
Sorry if i missed the whole point.


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## scolley (Apr 4, 2004)

To correct my last post...

If you dig, you can find pics of the _external _ reactor on Tom's site. They are not in the place the link points to, but drilling further into the Admin picture galleries show it.

Now that I've seen the picture, I'm disappointed to see that by _external_, Tom meant _in-line_. Unfortunately it's a HOB. And FWIW, it does not seem to have the important bypass to deal with the excess gas buildup. 

I would love to know how to convert an in-line to do what is described in this thread.


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## Hypancistrus (Oct 28, 2004)

I linked ADA because that's what's in the pic. The technique is not exclusive to ADA, and my impression is this is the technique that Tom is discussing.

Here's some other places that sell ones at different prices and quality:

Aqua Buys - http://www.aquabuys.com/miva/mercha...co2_diffuser&Category_Code=i3&Product_Count=1 - $14.99
Aquarium Landscapes - http://www.aquariumlandscapes.net/w...Row=26&ID=587C56FE-A1BC-48AE-AEB4F8F3ED61B39D - $38 - $106
Drs. Foster & Smith - http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=9915 - $19.99

I'm sure there's more from various shops around the net but those are the ones of I know of offhand.


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## scolley (Apr 4, 2004)

Hypancistrus said:


> OK, now I'm seriously confused by what you mean. I thought the whole point of this thread is that diffuser discs work better than reactors? Am I missing something here? :icon_conf


It's also about how to accomplish what Tom is describing. diffuser discs is one possible route. And it appears Oqsy has a different one. And Tom is describing his in-tank reactor that does it too.


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## jgc (Jul 6, 2005)

> Originally Posted by plantbrain
> 
> _You can make a purge loop for external reactors by making a hole 1/2 down and running the air line back to the intake for the power head, caniter filter etc, this will not add bubbles but will reduce the gas build up inside the reactor.
> 
> ...


His intank reactor has a powerhead pointing down. He is connecting a burp hole in the reactor (the hole that gets rid of excess undisolved gas) to the venturie of powerhead. Net effect is that instead of burping large bubles out the side of the reactor, it "burps" a micro mist of bubles that go right out the bottom of the reactor. His reactor is still disolving a lot of co2, but it now micromisting the excess gas back into the aquarium. 

The disk also micro mists - putting flow over the top of this provides better dispursement (the powerhead mist probably has pretty good dispursement as well, and is located near the bottom of the tank b/c of the nature of the reacctor). 

That said - am currious if the micro mist of the disk is finer than the venturi or not. Am curruious if I should remove the reactor and just micromist via the venturi. Am currious about the whole compressed air idea. Inquiring minds want to know more.


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## BSS (Sep 24, 2004)

Wow! I'm glad I'm not the only one that is confused about all of this. I've never used a venturi, and a diffuser sounds like it should be more high tech than it really is. I did a fair amount of reading and thinking about this one last night, so let me share my current thoughts.

First, I think the venturi stuff and all the mods to external reactors is really just confusing this topic. In Tom's first post, he talks about "I'd suggested..." meaning to me that he used to suggest how to make reactors better. But, I don't think this is really germaine to this discussion.

IMO, this whole 'new' idea is to just turn the CO2 into small, pure CO2 bubbles and then make sure it is in the filter output stream so that it gets pushed around the tank. Oqsy basically did this by feeding his CO2 line into the inbound side of a powerhead, so it chopped up the bubbles (a 'high-tech' diffusor :wink: ). He then used some modified tubing to help disperse things a bit better.

For a test, I believe I can accomplish what Tom suggests by taking my XP3 spraybar and converting it from a horizontal position to a vertical position in the corner of my tank near the filter inflow. Then attaching an airstone to my CO2 line and sitting it at the bottom of my tank near the output of the new vertical spraybar.

After thinking about this last night, I really do think it is that easy! Do others agree/disagree?

I'm also hoping to call Aquatic Eco-Systems today (since they are local for me) to see if they can start stocking the Azoo CO2 diffuser, which Tom suggests as being a good one. I've seen it on another site for around $20. So, stay tuned on that front.


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## BSS (Sep 24, 2004)

jgc said:


> Net effect is that instead of burping large bubles out the side of the reactor, it "burps" a micro mist of bubles that go right out the bottom of the reactor. His reactor is still disolving a lot of co2, but it now micromisting the excess gas back into the aquarium.


Then again...maybe I have some more thinking to do :icon_roll !


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## Jason Baliban (Mar 3, 2005)

I think you are on to it BSS. I think the topic has been expanded by talking about why to do it this way, and also what are the different ways to get it in the tank. As you were saying though, I think the point is get the bubbles as small as possible and get them around the tank.

Anyone use a skimmer before? Dont they create rediculously small bulbbles? Can't we modify one of those to create a CO2 mist? The buoyancy of micro bubble is so small that they almost suspend in the tank then float up. If we could get this "mist" around the tank.....BAM!!....I think that would be the cat's meow.

jB


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## scolley (Apr 4, 2004)

Jason, IMO discussion of how to accomplish this is not off topic. Go back to Tom's first post. He did not start a conversation exclusively about theory, or exclusively about technique. He covered "What", "Why", and "How".

The "What" is still being defined here. The "Why" is the theoretical dialog. And the "How" is the only reason to have the conversation. If we can't advance to the question of how to get it done, I think we're just wasting time.

What - Why - How - It's all a part of Tom's original post.


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## Jason Baliban (Mar 3, 2005)

I agree with you scolly. I may have to rewrite my post if I came off that way. Just more supporting BSS in......


bss said:


> IMO, this whole 'new' idea is to just turn the CO2 into small, pure CO2 bubbles and then make sure it is in the filter output stream so that it gets pushed around the tank.


My wild skimmer idea is just another idea to accomplish this.

Thanks

jB


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## jimmydrsv (Apr 8, 2005)

Skimmers are dependent on a higher salinity concentration i thought. Such a thing isn't suppose to work in a freshwater setup.


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## Bert H (Dec 15, 2003)

> His reactor is still disolving a lot of co2, but it now micromisting the excess gas back into the aquarium.


 Having some difficulty here, does this mean then that the tanks will look like a champagne glass with CO2 bubbling all through the tank?  

It seems to me, the only way to accomplish this is by having more 'stuff' inside the tank, which is something I have been minimizing every way I can - external heater, external reactor, etc. Am I missing something here??


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## jgc (Jul 6, 2005)

Having some difficulty here, does this mean then that the tanks will look like a champagne glass with CO2 bubbling all through the tank?​
Mine already does  My substate keeps pearling :icon_redf


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## Left C (Nov 15, 2003)

Would this diffuser/air pump probably work like Mr. Barr explains? It comes in four sizes. You could hook it up to a CO2 tank instead of using the atmosphere for air. You probably need some current to blow the bubbles around.

It's: http://www.hydor.it/index_en.htm and go to air pumps then Ario. Heck they got these dern things with colored lights too. :icon_roll Go to Ario Color.

It's available at: http://www.marinedepot.com/aquarium_air_pumps_hydor_ario_turbo.asp?CartId=


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## Hypancistrus (Oct 28, 2004)

Jason Baliban said:


> Anyone use a skimmer before? Dont they create rediculously small bulbbles? Can't we modify one of those to create a CO2 mist?jB


A skimmer, minus the latest refined design techniques, is basically a HOB filter with an airstone in it. In water with high salt and high dissolved organics, this makes a lot of froth, so there's a place for the froth to bubble over into and collect. The froth contains most of the organics. I think part of what makes the bubbles looks so small here is the high salinity of the water.

For a FW application, you could simply put a ceramic diffuser disc in a HOB filter. But then you have water being swished about after the bubbles are introduced, which is basically more like a reactor... it dissolves the CO2 rather than keeping it as bubbles. This is why you see people like Amano putting the diffuser discs _inside the tank_. Plus, if you look at the pics from the gallery thread, you'll see he has the diffuser discs on the _opposite side_ of the inflow/outflow on all of his tanks.

A lot of this discussion seems to be drifting towards ways to get the bubbles smaller and smaller and put directly into the flow/current, which leads to basically being ways to _dissolve_ the CO2, which is against the hypothesis that Tom posted and is being discussed here.


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## Hypancistrus (Oct 28, 2004)

Left C said:


> Would this diffuser/air pump probably work like Mr. Barr explains?


I would say you'd be better off with the CO2 diffuser discs. That Hydor Ario thing is designed to dissolve atmospheric oxygen, which doesn't dissolve as easy as CO2. It doesn't hook up to an air pump, it simply sucks in air from a tube that sticks above the water, so if you hooked it up to a CO2 line it would likely cause problems. It would bascially be a more expensive and complex way to achieve the same results as with a diffuser disc.


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## esarkipato (Jul 19, 2005)

*finally*

finally, the end!

General question: Tom suggests that, through experience, he has boosted plant growth by providing co2 in the form of tiny bubbles, rather than circulating co2-enriched water. How much (what volume percentage) of the overall co2 bubbles entering the water column do you figure is being dissolved using this method?

Practical question: And the only explanation as to "why?" bubbles are better is because the micro-bubbles have 100% co2, while the water is only 30ppm co2? Shall we consider the fact that while the 30ppm water covers 100% of the leaves, the micro-bubbles cover about 0.0000001% of the leaf surface area?!?

Is it possible that the pure act of circulation is helping the growth, by evenly dispersing the co2?


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## esarkipato (Jul 19, 2005)

I forgot to mention my own method. picture at:
http://www.ernestjohn.com/images/Tanks 09-15-2005 016.jpg
The result is tons of almost microscopic bubbles emerging from the bottom of the gravel vac, and *slowly* floating up toward the surface. I have 2 crypts in the tank, one is near the co2 and one is not. neither shows better growth than the other. 

Also, I get little pearly, mostly on sunset hygro and java fern. could this be due to only 1x55watt PCF over the 29gallon? (sorry if this is off track)


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## brad (Aug 11, 2005)

esarkipato said:


> How much (what volume percentage) of the overall co2 bubbles entering the water column do you figure is being dissolved using this method?


I think that`s the point. The bubbles aren`t dissolving. They`re being held up by the plants.

Tom, I really think you need to ring in here and make sure we`re understanding.


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## Wasserpest (Jun 12, 2003)

scolley said:


> I would love to know how to convert an in-line to do what is described in this thread.


I don't think you can. The micro bubbles are created by running them through the impeller, repeated times if they are still too large. The finest bubbles come out on the bottom of the reactor, the larger ones collect on top and get sucked back via the loop into the impeller.

Can't do that with an inline reactor, unless you have a way to feed the CO2 into your canister AFTER the filter media and BEFORE the impeller. Drilling holes into your canister and risking an airlock anyway is something to try for braver ppl.

Impeller chopping up bubbles makes noise. And yessssss your tank will look like a Champagne bath. I went away from this to keep things quiet and clear. But if you're not happy with plant growth even at 30 ppm, definitely give this a try...


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## scolley (Apr 4, 2004)

Wasserpest said:


> I don't think you can. The micro bubbles are created by running them through the impeller, repeated times if they are still too large. The finest bubbles come out on the bottom of the reactor, the larger ones collect on top and get sucked back via the loop into the impeller.


Thanks Wasserpest. But I wasn't referring to a rig injecting CO2 into a filter. I was referring to your garden variety in-line reactor (some will call it a diffuser). By either name, just the in-line tube with bio-balls (or whatever), that CO2 is into to be dissolved by the on rushing water.

Gotta be a way to convert one.


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## Wasserpest (Jun 12, 2003)

scolley said:


> I was referring to your garden variety in-line reactor (some will call it a diffuser).
> ...
> Gotta be a way to convert one.


I know... that's what I was referring to as well. Only way to get "Toms famous micro bubbles" would by by sending CO2 (perhaps repeated times) through the impeller. And suck the larger ones collecting in our garden variety inline reactor back into the impeller. Like I said, not really practical with our average setup: canister filter and inline reactor.

Really easy with a powerhead-powered reactor. Aka eyesore. :tongue:


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## jkolb (Mar 30, 2005)

scolley said:


> Thanks Wasserpest. But I wasn't referring to a rig injecting CO2 into a filter. I was referring to your garden variety in-line reactor (some will call it a diffuser). By either name, just the in-line tube with bio-balls (or whatever), that CO2 is into to be dissolved by the on rushing water.
> 
> Gotta be a way to convert one.


I think the "conversion" wouldn't be much at all. I seems the equivalent inline system would be inject the CO2 directly upstream of your pump. The pump chops up the big bubbles into tiny ones and spits them straight into the tank (probably with the spraybar blowing down). Hopefully it's a pretty straight shot back up into the tank. The "reactor" ceases to exist. It's your tank.


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## jkolb (Mar 30, 2005)

Wasserpest said:


> Like I said, not really practical with our average setup: canister filter and inline reactor.
> 
> Really easy with a powerhead-powered reactor. Aka eyesore. :tongue:


You could put a small pump inline (like a Maxi Jet) and inject CO2 right before it. 

Canister filter->CO2->Pump->Tank

That shouldn't be too hard. Maybe a little hard for just an experiment though. :tongue:


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## jgc (Jul 6, 2005)

Seems to me an inline diffusser is possible - just rig it so it causes the bubbles to jet out instead of being caught in turbulance. Likewise a bit of modifications to the spray bar should let the bubble exit the bottom while giving some flow over the entire bar. Worse case, split the output with bublles being released on one at the bottom of the tank and the rest going through the verticle spay bar.

Curse I keep thinking if I rap that mess in something, maybe I can get some moss to grow in it and really camoflage it... :icon_conf


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## Hypancistrus (Oct 28, 2004)

Wasserpest said:


> Only way to get "Toms famous micro bubbles" would by by sending CO2 (perhaps repeated times) through the impeller. And suck the larger ones collecting in our garden variety inline reactor back into the impeller.


Again, look at the Amano tanks:
































































The diffuser disc is as far away as possible from the flow. I think sticking CO2 into the flow or impeller is going to _dissolve_ it rather than produce bubbles, which is _not_ what we're after with this hypothesis.


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## scolley (Apr 4, 2004)

Hypancistrus said:


> The diffuser disc is as far away as possible from the flow. I think sticking CO2 into the flow or impeller is going to _dissolve_ it rather than produce bubbles, which is _not_ what we're after with this hypothesis.


Nice observation! Too bad it just means more stuff in the tank. :icon_frow


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## shalu (Jan 16, 2003)

I am a little surprised to see the diffuser so high in the tank. I expected to see it near the bottom so that the CO2 bubbles stay in the tank longer before they reach the surface.


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## bharada (Mar 5, 2004)

But unless you have a heck of a strong out flow from the filter the CO2 bubbles from the diffusers will simply rise to the surface. Tom,'s whole premise here is to get the CO2 bubbles under the plant leaves. I don't see how any of the Amano tanks would achieve that result as configured.


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## shalu (Jan 16, 2003)

I agree with you, Bill. Hypancistrus, thank you for posting those pics here. I assumed that Amano was doing the CO2 "optimally" and that he knew Tom's secret already. Now it seems he did not know it.


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## Momotaro (Feb 21, 2003)

Wonderful job illustrating your point, Hypancistrus.

Indulge my brain storming:

What would be the possibility of placing Venturi valve directly inline with a canister filters output? Doing something like that would certainly give you a fine mist of bubbles directly in your canister filter's out flow and circulate the fine CO2 bubbles throughout the aquarium without the need for a powerhead or more equipment in the aquarium. 

Of course you would need to modify the water's return to the aquarium. You'd have to eliminate the spraybar I imagine. You would also probably like to have the water return further down in the aquarium so the bubbles rise and come into contact with the plants as they are forced about by the canister output circulation.

Can anyone else see this? Can anyone help elaborate?

Mike


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## plantbrain (Dec 15, 2003)

My point is that Amano would do better to place the diffuses right under the outflow from the filter, opposite from the above examples.
The flow should be downward with only a small fraction creating some surface turbulance.

I do not like Lily pipes, not the intakes/outflows, they break very easily. Ask me how I know that one..............After spending $$....what a waste.......

The plastic spray bar is much more even in the distribution of current also. Amano sacrifices that for aesthetics, but a tube going down and across the rear is not unattractive either.........

I place the diffuser(or venturi reactor) down low near where the flow is.
Size of the bubble counts, the finer, the better.

I've also noted a couple of tanks that did much better as soon as the owners placed the outflow to blow the mist all over the tank recently.

Rather than discussing some of these other points, I'd suggest folks try the suggestion I've made, then you can argue about why it works............

Current, mist(not some cheesy junk air stone, large cheap venturi that comes with the powerheads etc), you need fine mist. You need good current/flow as soon as it comes out of the disc/reactor.

About the external reactors: it's just a design feature I add to allow folks to purge their excess gas that builds during the day. The gas will put a flame out BTW that builds up, so it's not O2 (so what other gas builds up in there that's in excess? Give it some thought and why might bubbles persist a long time after an hour or two around the tank).
You can fashion a pretty good venturi for external reactor purging that will produce good mist. 

FYI, the amount of pearling is much more than Amano's pics show in his pics vs my tanks doing this routine/CO2 method.

I'm not sure why he'd place it as far away as he could.
Seems the worst place based off my observations.
But CO2 is cheap....and those disc are large and likely cleaned often.

Regards, 
Tom Barr


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## plantbrain (Dec 15, 2003)

Momotaro said:


> Wonderful job illustrating your point, Hypancistrus.
> 
> Indulge my brain storming:
> 
> ...



Mike, I made this suggestion a few times, but, it reduces the flow and increases the pressure needed to runa good venturi valve like say Kent's version.

But you can make your own and put a large bubble counter as a reservior and make a rigid airline tubing splice into the return line that would do fairly well.

I still think the disc or inhternal versions work better.

I'll keep after it.

Regards, 
Tom Barr


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## scolley (Apr 4, 2004)

I'm highly attracted to that concept Momotaro-san. But I think Wasserpest was indicating earlier that trying to do that would just cause the micro-bubbles to be absorbed into the water. I think.  Because I _love _ the concept you are suggesting!

PS - How do I delete a post? Tom ninja-posted while I was replying, and made my point above moot. I think.


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## stcyrwm (Sep 1, 2005)

Tom suggested using Azoo microbubble diffuser as low cost alternative to ADA diffuser. Anyone know where to buy one or have suggestion for comparable quality unit? Google has failed me for once.


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## unirdna (Jan 22, 2004)

plantbrain said:


> Rather than discussing some of these other points, I'd suggest folks try the suggestion I've made, then you can argue about why it works............


Fair enough. I've ordered all the knicks and knacks to do this properly. Should have it going on my 30g or 50g by mid next week. I am a sucker for an experiment.

....We'll get to the "why" soon enough .


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## Tino (Jan 9, 2005)

stcyrwm said:


> Tom suggested using Azoo microbubble diffuser as low cost alternative to ADA diffuser. Anyone know where to buy one or have suggestion for comparable quality unit? Google has failed me for once.



You can get one here http://cgi.ebay.com/Azoo-CO2-Diffus...oryZ3212QQssPageNameZWD1VQQrdZ1QQcmdZViewItem

On Amano's tanks: large ceramic discs (like Tom pointed out) and excellent water circulation take care of the job. CO2 gas in direct contact with the plants (as opposed to the reactor premixed version) seem to work just fine for him.


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## Hypancistrus (Oct 28, 2004)

bharada said:


> But unless you have a heck of a strong out flow from the filter the CO2 bubbles from the diffusers will simply rise to the surface. Tom,'s whole premise here is to get the CO2 bubbles under the plant leaves. I don't see how any of the Amano tanks would achieve that result as configured.





shalu said:


> I agree with you, Bill. Hypancistrus, thank you for posting those pics here. I assumed that Amano was doing the CO2 "optimally" and that he knew Tom's secret already. Now it seems he did not know it.





plantbrain said:


> My point is that Amano would do better to place the diffuses right under the outflow from the filter, opposite from the above examples.
> The flow should be downward with only a small fraction creating some surface turbulance.


I would also tend to think that in the above examples, the inflow tube and diffuser disc ought to swap places.

Despite all of this, look at how the tanks are doing! :hihi:


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## jimmydrsv (Apr 8, 2005)

I am not sure this is useful but i am posting it anyways.

From what i have noticed from the flow in my tank, what you immediately see is that the water shoots straight back up after it shoots out of the outlet. I am guessing this is caused because the expelling of water in one direction causes a vacumm which pulls back in water which is only intensified by the nature of water which is to pull on itself. 

Think about a wheel spinning or a convection current or if you were to insert your hand into a box of balls. In the balls perspective the ball is rolling back up against your hand as you insert it in. Having our bubbles shoot to the top of the tank again isn't necessarily helpful, correct?

I however notice a second thing occuring. As part of the water flow is expelled upward, i can see a second flow continuing down until it hits the glass and changes directionality 90 degrees and continues with a downward flow towards the substrate. 

If we were to place the co2 right where the outlet of the flow is then much of it would return to the top of the tank. However by having it across from where the immediate flow is, the bubbles or co2 in the water continues to shoot down toward the substrate. Despite the softer flow it may be more efficient. 

Hopefully this will make sense to someone or someone else can verify it with their own observations of flow in their tanks.

I think by looking at amano's tanks that what he might be doing is creating a circular flow of the co2 rather then just trying to shoot co2 at his plants.


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## Hypancistrus (Oct 28, 2004)

I would be willing to bet that the flow in the Amano tanks is something like this:










I am guessing he is trying to keep the bubbles out of the water where it is moving the fastest in order to keep the CO2 from dissolving.

Looking at the pictures again, he _does_ have some tanks where he _does_ have the diffuser placed on the same side as the flow:





































The difference between these tanks and the other tanks is they are _very large and/or long_. In these cases, by the time the "wheel" would make it over to the diffuser disc if it were mounted on the other side of the tank, the flow would be _too_ weak to carry the CO2 back across.

Based on this evidence, I would surmise that Amano is indeed trying to keep the CO2 as small bubbles and not dissolve it. Perhaps this is indeed something that he has known for quite some time, but never really shared in any of his books or lectures (which is quite sad really, if it is true).


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## Left C (Nov 15, 2003)

Hypancistrus said:


> I would say you'd be better off with the CO2 diffuser discs. That Hydor Ario thing is designed to dissolve atmospheric oxygen, which doesn't dissolve as easy as CO2. It doesn't hook up to an air pump, it simply sucks in air from a tube that sticks above the water, so if you hooked it up to a CO2 line it would likely cause problems. It would bascially be a more expensive and complex way to achieve the same results as with a diffuser disc.


When I got home last night and found the O2/CO2 diffuser discs in my Aquatic Eco catalog, I saw what you are talking about- 100 micron or so bubbles.


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## bharada (Mar 5, 2004)

I'd be willing to bet that Mr. Amano has never even considerd trying to get micro-CO2 bubbles into the plant matter.

My extrernal reactor on my high light 40g tank will occasionally discharge tiny CO2 bubbles while I'm goofing around in the tank stand. The spraybar in this tank is located horizontally on the substrate in the back of the tank directed up. Even being blown upward by the water flow, all the bubble are dissolved before reaching the surface. So you expect me to believe that the gentle flow in Amano's tanks has the power to keep CO2 bubbles from dissoving while it makes a total circuit of the tank? :icon_roll

Tom's initial premise may have merit, but diffusing CO2 bubbles into a tank does not equal forcing said bubbles into the plants…which is the whole point to Tom's intital post. It's not the bubbles folks, it's where the bubbles end up so please stop posting pictures of Amano tanks thinking that those are the proof to Tom's theory.


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## Hypancistrus (Oct 28, 2004)

bharada said:


> My extrernal reactor on my high light 40g tank will occasionally discharge tiny CO2 bubbles while I'm goofing around in the tank stand. The spraybar in this tank is located horizontally on the substrate in the back of the tank directed up. Even being blown upward by the water flow, all the bubble are dissolved before reaching the surface. So you expect me to believe that the gentle flow in Amano's tanks has the power to keep CO2 bubbles from dissoving while it makes a total circuit of the tank? :icon_roll
> 
> Tom's initial premise may have merit, but diffusing CO2 bubbles into a tank does not equal forcing said bubbles into the plants…which is the whole point to Tom's intital post. It's not the bubbles folks, it's where the bubbles end up so please stop posting pictures of Amano tanks thinking that those are the proof to Tom's theory.


I have no idea why my participation on these boards always gets so brutally attacked. Am I just cursed? 

If the Amano tanks "aren't working," why are they doing so well?

Sorry I posted anything.


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## BSS (Sep 24, 2004)

Left C said:


> When I got home last night and found the O2/CO2 diffuser discs in my Aquatic Eco catalog, I saw what you are talking about- 100 micron or so bubbles.


Hey Left C (or any others!),

Do you happen to have the part numbers or descriptions of those parts. I'm not 100% sure what I'm looking for, but as I actually live about 10 miles from Aquatic Eco, I was going to drive over there next week. I was leaning towards the AS101 from this page http://www.aquaticeco.com/index.cfm/fuseaction/product.detail/iid/9775/cid/2339.

It might be a bit overkill, but my thought was it might also go longer between cleanings :wink: , and I believe per one site I saw the cleaning process is via a muratic acid soak (which I happen to have for my pool).

Thanks!


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## AlexPerez (Jan 25, 2004)

> It's not the bubbles folks, it's where the bubbles end up so please stop posting pictures of Amano tanks thinking that those are the proof to Tom's theory.


I don't think the pictures are trying to prove Tom's theory. What they are showing is the circulation caused by the lily pipes. I have lily pipes on my tank (not ADA) and I do see the same general circulation as demonstrated in the pics. Now whether that circulation is
sufficient to implements Tom's idea I don't know.


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## bharada (Mar 5, 2004)

AlexPerez said:


> I don't think the pictures are trying to prove Tom's theory. What they are showing is the circulation caused by the lily pipes. I have lily pipes on my tank (not ADA) and I do see the same general circulation as demonstrated in the pics. Now whether that circulation is
> sufficient to implements Tom's idea I don't know.


Then let's keep conversation on the efficiency of using ADA lilly pipes and diffusers in its own thread.

What Tom proposed in his OP was that plant growth rate increased by getting fine CO2 bubbles in contact with the leaves, allowing for a more efficient absorbsion rate of C. Then someone jumped in with an offhand comment that Amano, with his diffusers, must have known this all along.  All of a sudden this thread flew off topic, now bent on extolling the virtues of using a glass diffuser...something that was not even part of Tom's internal-bubble-making-machine plan. :icon_roll

Now if everyone here wants to go off and start using diffusers and lilly pipes more power to them. But this thread seems to be doing a great disservice to all those folk who are keeping increadibly beautiful planted tanks using just a lowly external CO2 reactor.


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## esarkipato (Jul 19, 2005)

I see this thread becoming more a question of "how do we get microbubbles in contact with as many leaves in the tank as possible?" (aside from theoretical discussions). To that end it helped me to look at amano's application of lily pipes, to see what may/maynot work. No need to get so worked up bharada!


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## plantbrain (Dec 15, 2003)

I think the ADA stuff does show some thing that are/were normally considered. If you want better dissolving, place a diffuser near a power head, filter flow etc, he does this on the larger tanks etc.
This has been suggested long before ADA was even thought about in the West. 

Nothing new there.

What I'm suggesting is different than the ADA/Ehiem notion.

I can measure the dissolved CO2, the O2 and also try and dissolve every last CO2 bubble.

I'm suggesting folks try this for themselves, much like I suggested adding PO4 about a deacde ago.

Place the spray bar in a vert position(hides it better anyway), slightly downward if you want, place the diffuser at the bottom of this so the mist gets blown away.

You'll see the mist dissolve initially, then after an hour or two, the mist will start to get blown around and persist more(the same thing occurs in reactors).

Ask yourself why that might be....................
Just try it yourself and observe closely and then consider what I've said.

Is it easier to dissolve CO2 into water that is 3ppm or 30ppm?
If you want to increase the rate of dissolution, it is better to have a larger concentrational gradient.

As we get higher CO2 ppm, this concentration decreases, so the CO2 last in solution longer. 

CO2 is very souble, but it does have it's limits.
How they affect this observation in our tanks is not particularly clear to me.
I've offered a hypothesis, I'm not saying it's right or wrong, but I've found little else to explain the observation.

I can test whether this is the case or not, but it will take more than a simple test kit etc.

I can say the growth rate is dramatically different with this method(Using a DO meter to measure O2 production solely from the plants).

BTW, many of you think a nice aquascape = a good method, better method etc, they are in no way dependent on the other. Just because you have a nice scape does not mean the methods are perfect. It's "advertizing" and excellent photography as well. Neither Amano nor I have the time to do both scaping and science full time. 

Regards, 
Tom Barr

www.BarrReport.com


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## plantbrain (Dec 15, 2003)

bharada said:


> Then let's keep conversation on the efficiency of using ADA lilly pipes and diffusers in its own thread.


Agreed



> What Tom proposed in his OP was that plant growth rate increased by getting fine CO2 bubbles in contact with the leaves, allowing for a more efficient absorbsion rate of C.
> 
> But this thread seems to be doing a great disservice to all those folk who are keeping increadibly beautiful planted tanks using just a lowly external CO2 reactor.


I'm not suggesting externals etc do not work, I am saying you could do *better* if you desired. I know external reactors well, I've made and sold them for 10 years. Same with internals. I also know when I'm on to something.I've had this same tank for 15 years and it's one of my experiment tanks. I've added 100ppm of CO2 over long time frames without fish to observe plant health. I've still not seen growth like this and I have healthy fish. 

Given CO2's role and importance, it does warrant consideration.
I know my observations. I've never seen growth rates and O2 production like this ever. 

Nor am I suggesting lily pipes, ADA etc, the one's I got all broke with a little cleaning in the tank, I gently knock it against the side of the tank, CRACK! 80$ down the tubes.

Diffusers are cheap, External devices are in the works(and mighty Cheap and DIY etc), and internal misters like the venturi diffuser I've used and made for years can all be used.

I'd just suggest folks try it. Then you can haggle.
Very small bubbles, good flow charateristics(especially on larger tanks) are critical.

I would also add a word of caution, watch your fish, this often improves the CO2ppm in the water a fair amount as well(ask yourself why that might be....) 

Regards, 
Tom Barr


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## AaronT (Apr 11, 2004)

Tino said:


> You can get one here http://cgi.ebay.com/Azoo-CO2-Diffus...oryZ3212QQssPageNameZWD1VQQrdZ1QQcmdZViewItem
> 
> On Amano's tanks: large ceramic discs (like Tom pointed out) and excellent water circulation take care of the job. CO2 gas in direct contact with the plants (as opposed to the reactor premixed version) seem to work just fine for him.


That just goes to show you that ebay is not always the best deal. That same diffuser is $5.00 cheaper directly from their store. 

http://www.aquacave.com/co2_diffuser.htm


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## AaronT (Apr 11, 2004)

BSS said:


> Hey Left C (or any others!),
> 
> Do you happen to have the part numbers or descriptions of those parts. I'm not 100% sure what I'm looking for, but as I actually live about 10 miles from Aquatic Eco, I was going to drive over there next week. I was leaning towards the AS101 from this page http://www.aquaticeco.com/index.cfm/fuseaction/product.detail/iid/9775/cid/2339.
> 
> ...


I would not use those diffusers. The bubbles are actually too fine. Those diffusers need 25 psi to operate which is at 4 times the pressure used in the typical diffusers like the azoo or the eheim. If you want the try this I suggest you look for diffusers that operate at 0.5 bar or less. You are better off trying one of these: http://www.aquaticeco.com/index.cfm/fuseaction/product.detail/iid/9653/cid/2265 and the price sure is right.


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## Left C (Nov 15, 2003)

BSS said:


> Hey Left C (or any others!),
> 
> Do you happen to have the part numbers or descriptions of those parts. I'm not 100% sure what I'm looking for, but as I actually live about 10 miles from Aquatic Eco, I was going to drive over there next week. I was leaning towards the AS101 from this page http://www.aquaticeco.com/index.cfm/fuseaction/product.detail/iid/9775/cid/2339.
> 
> ...


I notice that you are getting responses to you question. I'm at the library now so I can't help you with any part numbers. I don't have the catalog with me. The only thing that I remember was they weren't cheap. $50-$80 or so if I was looking at the ones Mr. Barr mentioned. Sorry that I can't help.


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## plantbrain (Dec 15, 2003)

You can try the next size up from the micro bubblers. Not sure if they are like the diffusers like ADA's/Azoo etc.

Regards, 
Tom Barr

www.BarrReport.com


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## shalu (Jan 16, 2003)

It seems these cheap diffuser discs would work judging purely by the picture:
http://www.aquaticeco.com/index.cfm/fuseaction/product.detail/iid/9653/cid/2265


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## BSS (Sep 24, 2004)

grandmasterofpool said:


> You are better off trying one of these: http://www.aquaticeco.com/index.cfm/fuseaction/product.detail/iid/9653/cid/2265 and the price sure is right.


Thanks, GMOP, Left C, Shalu! I've never used bubblers/discs before, so it's new territory to me. As to the e-bay price GMOP mentioned, I noted that. Although the store shows the Azoo diffuser as 'Out of Stock' (or similar), while the e-bay auction at +$5 the price shows something like 16 units available. Hmmmm!!

Okay, the next (possibly, stupid) set of questions. First, I'm thinking that in this setup I ditch my SMS122 and take my regulator solenoid straight into my lights (or on a similar schedule anyway). I'm was thinking (though Tom's latest appends have me re-thinking :icon_conf ) that with this approach, you wouldn't get as much dissolved CO2 (e.g. bpm) and thus the 'established' EI target of CO2 >=30 ppm (I'm currently in the 50 range) wouldn't really apply. Whether that is the case or not and assuming the CO2 is on largely whenever the lights are on, how do I establish my CO2 flow rate? Should it be based on seeing pearling after X number of hours? Certainly, if critters start dying, I've set it too high. But, is there a 'target' to shoot for? And, conversely, what level would be too low? I like the idea of faster, healthier growth, but can I then back it off to a growth level that is 'better for me' by slowing the CO2 flow rate?

I'm guessing there's not enough hard data to really answer many of these questions, but I'd love to get folks gut feel for what they might shoot for. I'm definitely interested in trying this, and once I accumulate a few more pieces (though I might start with an available airstone over the weekend), I'll jump in with both feet and report any observations. I just want to make sure I'm thinking about this right.

As I stated in an earlier post, never having really dealt with a venturi whatever-it-is or a mister/disc thingy, I'm feeling a bit in the dark on this one still.

Bear with me :wink: ,
Brian.


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## scolley (Apr 4, 2004)

Brian - I'm dying to find out what your observations will be... but why would you ditch the SMS122? Doesn't that answer your questions about how much CO2 to apply?

Assuming you could take your CO2 line out of your needle valve (on a solenoid controlled by the SMS122) and run it straight to the ceramic disc? Then your controller would shut things down if (or when) you're giving it too much juice.

Or am I missing something here?


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## BSS (Sep 24, 2004)

scolley said:


> ... but why would you ditch the SMS122? Doesn't that answer your questions about how much CO2 to apply?


The way I'm thinking about it (and it's likely faulty :icon_bigg ) is that if the bubbles get blown around the tank, then they are not being dissolved (at least not as much as they were!). Therefore, the actual ppm of CO2 dissolved in the water could/should be less than I'm shooting for today. It seems to me, that there would be more readily 'absorbable' (is that a word :icon_roll ) CO2 swirling in the tank, but less of it would be dissolved thus leading to a lower ppm target (if it would even continue to apply!) Thus the reason for my questions.

Is anyone else thinking along these lines...or am I out standing in a field all by myself YET again :icon_bigg . Not that I mind it. It allows me to overthink things with fewer distractions :tongue: .


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## scolley (Apr 4, 2004)

Brian - I think you are asking the right questions. And I think Tom has alluded to the idea that this will affect pH, and you can't drive it too low.

But IMO, keeping your controller in the process still gives you some level of feedback and control. What you then need is an answer to "how much is too much". If you can get that, then IMO the controller will still be a valuable tool.


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## m.lemay (Jul 28, 2002)

BSS said:


> The way I'm thinking about it (and it's likely faulty :icon_bigg ) is that if the bubbles get blown around the tank, then they are not being dissolved (at least not as much as they were!). Therefore, the actual ppm of CO2 dissolved in the water could/should be less than I'm shooting for today. It seems to me, that there would be more readily 'absorbable' (is that a word :icon_roll ) CO2 swirling in the tank, but less of it would be dissolved thus leading to a lower ppm target (if it would even continue to apply!) Thus the reason for my questions.
> 
> Is anyone else thinking along these lines...or am I out standing in a field all by myself YET again :icon_bigg . Not that I mind it. It allows me to overthink things with fewer distractions :tongue: .


You're thinking is on the right track. I don't think the ph controller is necessarily useless. You just might wanna set it at a different(higher maybe) ph level to attain some measure of controll. As always...watch the fish for gasping.

I gotta tell ya that I'm a little skepticle on the practicality of this proposal. The idea of gas bubbles on the plants makes a lotta sense to me but it's execution might be rather complex in a larger tank setting. It would seem to me that some sort of under gravel manifold with diffusion disks scattered around the bottom of the tank would be the optimum way to go but then there's the problem of regulating the gas to each disk so that the first disks inline don't spew all the gas while the other disks are attempting to overcome the head pressure of the tank. I'm just babbling as I type.

Don't expect Tom to support me on the PH controller, he hates them. I think he has early childhood memories of ph controller abuse :icon_lol: :tongue: 

Marcel


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## Blue (May 29, 2005)

bharada said:


> I'd be willing to bet that Mr. Amano has never even considerd trying to get micro-CO2 bubbles into the plant matter.
> 
> My extrernal reactor on my high light 40g tank will occasionally discharge tiny CO2 bubbles while I'm goofing around in the tank stand. The spraybar in this tank is located horizontally on the substrate in the back of the tank directed up. Even being blown upward by the water flow, all the bubble are dissolved before reaching the surface. So you expect me to believe that the gentle flow in Amano's tanks has the power to keep CO2 bubbles from dissoving while it makes a total circuit of the tank?
> 
> Tom's initial premise may have merit, but diffusing CO2 bubbles into a tank does not equal forcing said bubbles into the plants…which is the whole point to Tom's intital post. It's not the bubbles folks, it's where the bubbles end up so please stop posting pictures of Amano tanks thinking that those are the proof to Tom's theory.





bharada said:


> Then let's keep conversation on the efficiency of using ADA lilly pipes and diffusers in its own thread.
> 
> What Tom proposed in his OP was that plant growth rate increased by getting fine CO2 bubbles in contact with the leaves, allowing for a more efficient absorbsion rate of C. Then someone jumped in with an offhand comment that Amano, with his diffusers, must have known this all along. All of a sudden this thread flew off topic, now bent on extolling the virtues of using a glass diffuser...something that was not even part of Tom's internal-bubble-making-machine plan.






plantbrain said:


> I addressed the O2 issue simply, I used a diffuser disk for CO2(no O2 gas build up occurs).
> But that did not do it __alone__.
> 
> I wondered why.
> ...


Mr. Barr IS USING a diffuser disc.

LOOK AT THE TANKS by Amano... do they look like they aren't doing well? Excellent growth, breathtaking appearance, hardly any algae at all... I think Hypancistrus hit the nail on the head.



bharada said:


> Now if everyone here wants to go off and start using diffusers and lilly pipes more power to them. But this thread seems to be doing a great disservice to all those folk who are keeping increadibly beautiful planted tanks using just a lowly external CO2 reactor.


Hypancistrus posted links where you can buy diffusers for $15. Tom's original post detailed USING A DIFFUSER DISC.

Hypancistrus's point I think isn't about "use Amano equipment," it's about the fact that you don't want to put the bubbles in too strong a current or you'll dissolve the CO2. He is saying "Hey, here are some pictures where diffuser discs are being used and the tanks are very successful! Here is why I think that is..." Those tanks in the showroom use Superjet filters. It may not be *super strong* current, but it is definitely NOT weak. I know, I've visited the showroom more than once.

The larger Amano tanks shows exactly what Mr. Barr proposed.


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## stcyrwm (Sep 1, 2005)

Hypancistrus said:


> Sorry I posted anything.


Photos were helpful to me. Folks have talked about how helpful it is to be a member of a club and get to see other tanks. My nearest club meets over 3 hours away. This is my club. Someone asked for help visualizing ideas about this and you provided some possibilities for brainstorming. I get there may be some folks who don't need this or want this but there are other great places like the barrreport.com where folks can have a more strictly scientific discussion.

As for the thread being taken away from it's focus, what I've noticed is that this thread is practically dead on every other place I've seen it posted. Here it's cooking along with a conversation that I appreciate and seems very much in line with the idea of playing around with this strategy.


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## jhoetzl (Feb 7, 2005)

OK, I am going to do the ladder -> powerhead switch today.
Before I put it in my tank, I took some shots of it in action in a control environment.
Using a red sea powerhead (the one they use on the bottle kit they sell).

Have a look here:
http://www.geocities.com/jhoetzl/tank/co2test/co2test.htm


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## Momotaro (Feb 21, 2003)

> it's about the fact that you don't want to put the bubbles in too strong a current or you'll dissolve the CO2.


I think this is a very valid point. CO2 bubbles in too strong a current are going to dissolve, defeating the whole purpose. 

The Amano photos posted by Hypancistrus do illustrate the technique a bit in my eyes. Whether accidental or intentional some of those set ups look like they may be following this principal.

Marcel's idea seems interesting, I do see where the under-substrate manifold might be troublesome. Perhaps a couple of individual under-substrate set ups run off of one regulator with a manifold? You'd then have to get the bubbled further distributed in the aquarium...powerheads?

I think Tom observations here is great! I believe it is a potential innovation for plant growers once we get all the CO2 distribution bugs worked out, but lees of a boon to the aquascapers. Growers are going to appreciate increased plant growth, while aquascapers are going to try and struggle with more gadgets in the aquarium and how to hide them. That is why I think exploring Hypancistrus' correlation between this concept and Amano's practices are pretty darn important.

Mike


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## Hypancistrus (Oct 28, 2004)

Thanks for the support (some of you) guys.

I disconnected my Aqua-Medic Reactor 1000 today and attached the CO2 line to a $20 CO2 glass diffuser disc I had lying around, it's just like the one available from aquabuys.com.

I put it in the mid-bottom area underneath the water output. The way my tank is set up that really was the only place I could put it.

We'll give it a week and see how it goes.

I have also switched my CO2 from being on 24/7 to being on one hour before lights on and then off at lights out.

I have a pH probe / controller. I had the CO2 turned off long enough for the pH to go from 7.0 to 7.6, and it immediately began to drop again after I turned the CO2 back on using the diffuser disc.

My tank has fancy egg-shaped goldfish and one thing that might be a problem is the goldfish immediately began to develop a fascination with the CO2 bubbles. They are pushing each other out of the way for a chance to hold their heads in the mist. Hopefully this won't hurt them.


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## plantbrain (Dec 15, 2003)

Comments,


Hypancistrus (Or anyone for that matter), you should see a dramatic difference in a day, not a week if it's properly set up.

It'll take a little more tweaking to get the good diffuser disc rate going, but once done, you should see the dramatic growth.

Scapers........well, they need good growth too and better growth will make their lives easier and achieve the look they are after sooner.

Algae, well, this needs no comment, we all see the utility here.

Dissolved versus undissolved bubbles.............this is where folks are getting boondoggled.

Yep, you are.

The initial few minutes/hour/s(typically 1 to 3 hours after the light/CO2 comes on) are mainly dissolving the CO2 into solution.

Once a high level builds up, then it becomes much more difficult for the CO2 mist to be dissolved.

Chemically: it is more difficult to dissolve a substance against an increasingly larger concentrational gradient.

So in the AM when the lights first come on, the CO2 is poor and the gas rapidly dissolves entirely.

Say we get up to 30ppm dissolved in one hour.
Great, plants are bathed in a rich CO2 solution.

Still the same and works well as what was previously discussed for the last 40 years.

Now, what about the CO2 bubbles at 30ppm?
Are they so quick to dissolve?

You are adding CO2 to a solution that is already super saturated.
After 1-2 hours, the micro bubbles will persist and float around the tank.

This is true for my venturi reactors.
That gas build up in the external reactor tubes as well as the internal venrturis are similar later in the day.

Think about what that gas might be, I'd suggested it was O2, the flame test was not conclusive.

I could see the external reactors perhaps building up O2 later in the day, *but what about the internal venturi reactors?

No way, there's nothing to degas O2 in there!!!!!!!!!!!!!!!!!!!!!!!!*

So this means, and I know I'm right(rare), that the CO2 dissolving is greatly reduced later at a styable given CO2 dosing rate in the day after you build up to a certain level. What level? I'd guess about 30ppm.

After you get this into the tank, then this CO2 micro bubble theory starts to work.

You still have 30ppm in the tank, but now you have added pulse of pure CO2 mist on top of that.

It is not one or the other, they are synergistic, one complement and builds on the other.

My mistake in the past was assuming that the gas in the tube was O2, it's not, it's CO2 excess that's much more difficult to dissolve.

I tried this without any plants(thus no O2 build up), I had gas build up later in the day, thus reduction in CO2 dissolving at higher ppm levels.

............so there.

I finally figure out why that dang little venturi diffuser worked so good, only took me 12 years ! haha

Regards, 
Tom Barr


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## fishyface (Oct 7, 2004)

m.lemay said:


> You're thinking is on the right track. I don't think the ph controller is necessarily useless. You just might wanna set it at a different(higher maybe) pH level to attain some measure of controll. As always...watch the fish for gasping.Marcel


my observations since trying this method is that i've lost several fish since my controller remained on the same setting as with the external reator. never saw any gasping etc. but i've had to adjust it .2 degrees higher than i was running it before. also, i seem to be running co2 nonstop during photo period now as this diffuser method seems to have a hard time driving pH lower as fast.


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## plantbrain (Dec 15, 2003)

I do hate controllers.
I broke up with one not long ago

Regards, 
Tom Barr


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## scolley (Apr 4, 2004)

plantbrain said:


> Now, what about the CO2 bubbles at 30ppm?
> Are they so quick to dissolve?
> 
> You are adding CO2 to a solution that is already super saturated.
> After 1-2 hours, the micro bubbles will persist and float around the tank.


So, to bring this back to my personal obsession - getting crap out of the tank - Tom's observations would indicate that it might be possible to get this working on external in-line reactors... that after some level of saturation occurs (30 ppm?), then injecting this mist into an in-line setup _would not dissolve all the mist _ - that it might actually make it to the tank and have a chance to circulate. 

This sounds like good news to me.


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## Hypancistrus (Oct 28, 2004)

> So this means, and I know I'm right(rare), that the CO2 dissolving is greatly reduced later at a styable given CO2 dosing rate in the day after you build up to a certain level. What level? I'd guess about 30ppm.


My reactor1000 always filled up to the top with water when I initially turned CO2 on, then after a few hours would develop gas in the top. I've always wondered why. This must be it.

Today after I disconnected my CO2 from the reactor and hooked it up to the diffuser disc, I didn't disconnect my reactor. I just plugged up the top where the CO2 used to go in. No more gas build up in the reactor!

So what I am seeing here does follow what you are saying.


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## Laith (Jul 7, 2004)

Hypancistrus said:


> My reactor1000 always filled up to the top with water when I initially turned CO2 on, then after a few hours would develop gas in the top. I've always wondered why. This must be it.
> 
> Today after I disconnected my CO2 from the reactor and hooked it up to the diffuser disc, I didn't disconnect my reactor. I just plugged up the top where the CO2 used to go in. No more gas build up in the reactor!
> 
> So what I am seeing here does follow what you are saying.


Maybe a bit off topic but here's a post that I posted in an other forum regarding this:

--------------

Don't know if this is something that people are already doing or whether there's a reason people are not doing it...

I use the Aqua Medic 1000 external CO2 reactor on several setups. Depending on the set-up and CO2 settings, I usually get from time to time a small to large bubble of gas (CO2 and/or O2) in the top part of the reactor.

The AM 1000 comes with a purge valve on top so up until now I've attached a short tube to this and purged the thing into a jug from time to time because the noise was driving me nuts. Plus I would guess that the efficiency of the reactor is reduced when this bubble is present.

Then in reading about Tom Barr's internal venturi reactor I thought why not try something similar here? I attached a 1.5m length of silicone tubing to the purge valve and ran this tubing back into the aquarium. By leaving the purge valve open slightly, any excess gas buildup automatically escapes up the tubing and into the aquarium; no more gas buildup!

On another setup I'm going to do the same thing but instead of bringing the purge tube into the aquarium, I'll plumb it into the return hose after the reactor using a T fitting (similar to what I'm using for auto dosing ferts). This should work as well.

Please don't tell me that this is what everyone was doing with the purge mechanism of the AM 1000 anyway!

Don't know why it took me so long to try this... getting old

-----------------

Works great.


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## scolley (Apr 4, 2004)

Laith - I think that earlier in this thread, Tom (or someone) was indicating that if you took your "bleeder hose" and inserted it into your water hose, before it goes into your reactor - you could create a venturi effect with the excess gas and create some bubbles that would go into the tank. That requires positioning the air hose going into the water hose being positioned in a certain way. And while it might get some bubbles into the tank, it might not be the micro bubbles needed unless it was run through an impeller, like with a powerhead, or run through a ceramic disk.


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## scolley (Apr 4, 2004)

*New thread for DIY in-line micro-bubble addition*

FYI - I've started a new thread on how to accomplish this specifically in-line to stop impacting this thread. If you are interested, you can find that new thread here.


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## bigstick120 (May 23, 2005)

any follow up to those that have tried this new method??


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## BSS (Sep 24, 2004)

I need to document my findings....though the notes have been sporadic. Life just keeps doing that to me as of late :icon_roll !


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## scolley (Apr 4, 2004)

Did anyone ever get proof positive that this works? This surfaced last fall, caused no small amount of posting, testing, and arguing. And I must admit that I haven't been paying close attention in the last few months, but it looks like this just kinda died on the vine.

Did this go anywhere? Did anyone validate this over a month or more to confirm some of the initial claims?


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## plantbrain (Dec 15, 2003)

I've had many folks do this and then start complaining about all the pearling, rapid plant growth, and no algae.

I mean it's a very simple idea and very simple method to try, simply place a limewood stone below the spray bar filter output, blast the mist downward into the plant beds.

Then you tell me if you cannot see a dramatic difference or not.
That, rather than arguing is going to make it a regular useful method.

It's also the cheapest CO2 method next to the filter intake method. 
Nor is it difficult to ascertain if the bubbles from all the pearling are merely air since we know if the plants are actually growing or if they just have bubbles attached to them.

You can see the planmts grow, maybe a newbie cannot tell the difference, but most everyone else can after a few days.

You can measure the O2 levels and you can compare the CO2 ppm.
The increase in O2 and the increase growth with a similar CO2 ppm sure suggest the bubbles are CO2.

I can use a fine limewood air stone and watch the mist rise up slowly and dissappear, then I can add current and watch the same bubbles get blasted all over the tank. The difference is intense pearling and increase growth/O2 levels.

I don't have to argue for it, the proof is in the pudding.
I have not had anyone say it has not done what I said it does for the plants, the pearling or the growth.

Well, except for those that have not tried it.

Regards, 
Tom Barr


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## scolley (Apr 4, 2004)

Thanks Tom!


plantbrain said:


> I don't have to argue for it, the proof is in the pudding.
> I have not had anyone say it has not done what I said it does for the plants, the pearling or the growth.
> 
> Well, except for those that have not tried it.


I'm afraid I'm in that group. I don't use a spray bar, so I suppose I'll have to finish my in-line rig (already bought the parts!) to try to accomplish the same thing - blowing small CO2 bubbles around the tank.

So, anyone else out there able to back this up? Tom seems pretty certain... sounds good to me. But is anyone here at PT ready to stand up and say "yeah - I tried it and it definately works!"


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## BSS (Sep 24, 2004)

scolley said:


> So, anyone else out there able to back this up? Tom seems pretty certain... sounds good to me. But is anyone here at PT ready to stand up and say "yeah - I tried it and it definately works!"


Perhaps I'm beginning to sound like a broken record, but once again, my mileage has varied. I have an Azoo diffuser, I orientid my spray bar vertically, and I like both changes and will keep it this way. BUT, I don't really get all that much pealing and my plant growth is not that much different than it used to be. Perhaps a bit better, but nothing spectacular. And, I still wrestle with BBA. Not real severe, but it's still there.

The only common thread I can find in most of my experieces to date is ME  . But, I sure feel like I'm doing most things right. But, my setup just continues to be 'different' (and, I'm guessing Jart and a few others can relate!).

So, in summary, I like the new setup. I like the more obvious circular flow. I like getting rid of the in-line reactor, because it makes the setup easier to prime and seems to help with overall flow. But, I'd be interested in seeing more bubbles, personally!

Brian.


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## Oqsy (Jul 3, 2004)

well i have some slightly different but related results to share. i tried tom's micro-bubble method with a profile 402 powerhead in my 55 gallon tank with a rena ceramic diffuser with pretty strong results. However, about 2 months after changing to this method, I got my first canister filter, and decided to give an inline reactor a shot, as I've never used one before, and was interested in seeing the difference myself (if there was any). I found growth to be about the same, but i feel that those comparisons might not be fair or valid since my plant load seemed to have hit the "critical mass" where algae just can't keep up not long after setting up my caninster with the inline reactor (rex rigg style). The interesting and unexpected part came next.

I noticed that although the water looked clear enough with the eheim, and plant growth was acceptable, I got a surface film that was a royal pain and quite an eyesore if you got anywhere near the tank. So, still having the profile powerhead, as well as a "nano" hydor, I decided to churn the surface a bit. surface film faded away gradually... then one night my co2 bottle emptied into the tank, and all my fish were gasping at the surface, or being blown aimlessly by the filter output (one of my discus was stuck to the eheim intake strainer). So I immediately turned on both powerheads and hooked them up to airlines that hung out of the tank over the rim, with tiny airline valves on the end to adjust the amount of air moving into the powerhead. I adjusted the intake to where there were LOTS of TINY bubbles of atmospheric air being pumped into the water column, and in a matter of a couple of hours, the fish seemed to be on the mend. Yeah, interesting story, but nothing new so far... watch your CO2 level in your tank and make sure the cylinder doesn't dump into the tank. most people with pressurized systems know that caution well. here's the new part...

out of laziness or paranoia (who wants to see a tank full of fish with white skin gasping at the surface? not me!), I left the powerheads running. I left the "tiny bubbles" pouring out of them. I kept saying to myself "it's a brand new CO2 bottle, you have a low pressure regulator (thanks rex), it's NOT going to dump, at least not anytime soon!"... but I couldn't bring myself to remove them. In the next two weeks, I experienced the most lush, colorful, and healthy growth so far, and "pearling" out the ears... in fact I had to double my iron and traces to fight the deficiencies that were cropping up all of the sudden. My CO2 input rate was no different than before, my dosing was no different, no lighting changes, no change in fish load or feedings, still on the same EI weekly water change routine... what was different? the bubbles. not CO2 bubbles, just bubbles from the powerheads. Granted, I still injected co2 to near 50ppm (assuming my test kits and eyes have any resolution whatsoever), but the saturation of the water with all of the atmospheric gas... O2, nitrogen, CO2, etc, *seems* to have been a catalyst for spurring much more intense and healthy growth in my tank. I'm now having success with plants that have always failed in the same setup... ie: ludwigia inclinata, rotala macandra, prospernica palustris (this is a new addition, but it's doing so well that I think I can call it a success), blyxa japonica, among others. Also of note is the number of plants that lived, but didn't flourish until recently... these include : ludwigia repens, ludwigia brevipes, ludwigia glandulosa, dwarf hairgrass, and lysimachia nummularia. I've been extremely reluctant to post this story for a couple of months because for starters, I can't explain how or why it would work, and secondly, it seems counterintuitive. If anything, I should be losing more CO2 by adding other gases to the water column, and increasing the surface turbulence. The *only* explanation I can come up with is something similar to an idea suggested early in this thread... the bubbles accumulate on the bottoms of the leaves (O2, nitrogen, CO2, whatever)... each of theses bubbles is a surface across which the CO2 can escape solution. Even if the bubbles aren't initially CO2, by increasing the concentration of CO2 in the water column (in my case, the inline CO2 injection), the bubbles that formed on the leaves (pearling or not) had a MUCH greater chance of filling with CO2, feeding the plants, and being replaced by O2 as they bubble off the plants to the surface of the water. I offer only anecdotal evidence, which in the world of science in not really evidence at all, but it seems that something curious is happening here, and I encourage those with the time and the means to investigate this idea more fully. Hope this is useful to someone...

Oqsy


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## Wasserpest (Jun 12, 2003)

Me thinks it's the added circulation...


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## wapfish (Oct 14, 2005)

An idea I've been floating for some time with Tom is that the "mist effect" might in fact be due to more to a reduction in photorespiration than to direct effects of CO2. Your observations fit in exactly with that idea. 

When oxygen levels get too high, photosynthesis can be negatively affected because the oxygen will start to compete with CO2 for the active site of the enzyme responsible for CO2 fixation (RUBISCO). Early in the day, when photosynthesis is just getting going, there's not enough oxygen around to matter, but later on, oxygen levels can get extremely high. In fact they can and do go to supersaturation. I've measured this in my tank and Tom agrees that he generally observes about 150% saturation. 

In all plants, photorespiration is a built-in inefficiency for the entire photosynthetic process, but at least in land plants, the oxygen is off-gassed and doesn't accumulate around the plant. This isn't true in an aquarium. Not only does the oxygen hang around in solution, it actually sits as a gas on the underside of leaves directly over the stomata (leaf openings) responsible for gas uptake/exit. Tom maintains, if my understanding is correct, that the CO2 mist increases the amount of CO2 gas over the stomata, and that gaseous CO2 is much more effective than dissolved CO2 at entering the plant and driving photosynthesis. This could well be true. HOWEVER, if this line of reasoning is correct, then it is also true that photorespiratory effects must be extremely important in aquaria for exactly the same reason. Oxygen bubbles sit right over the stomata and would be expected to have strong inhibitory effects on photosynthesis. Not only that, oxygen is undoubtedly exiting from all stomata all the time, so oxygen bubbles must in large measure be blocking the very openings that CO2 needs access to, and the oxygen will have to be removed before the CO2 can get in!

Anything that gets helps get rid of oxygen bubbles on the leaves or lowers the total amount of oxygen in solution without decreasing CO2 availability has to have a positive effect on photosynthesis. This is basic biology. Nothing fancy. A beneficial effect will occur even if the CO2 concentrations is kept constant because the CO2 doesn't have to compete as much with oxygen for RUBISCO. The only issue is how much practical benefit will derive from getting rid of the oxygen. Because the oxygen is sits as a gas right over the stomata, the guess is that it's likely to be significant indeed. Certainly enough to account for the beneficial effects reported for the mist effect.

What I think is happening in your case is that the fine mist bubbles are simply assisting in O2 removal from the leaves, and probably from the tank in general, leading to an increase in CO2 fixation. The mist bubbles do this probably by merging with the oxygen bubbles underneath the leaves and causing them to off-gas. It's also conceivable that the mist bubbles help to "precipitate" supersaturated oxygen out of solution. The lower limit for how much oxygen will remain in solution will be somewhere around saturation if there is constant aeration, which will be around 8 ppm.


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## Jeff5614 (Dec 29, 2005)

Having kept fish for over 30 years I just started a heavily planted tank in December. I have DIY CO2 in 55 gallon. I know, you're gonna tell me pressurized is much easier, lol, but it takes 15 minutes every couple of weeks to change out bottles so I'm okay with it so far.

Anyway, back to the reason I'm posting. I use a limewood diffuser placed beneath my spray bar. It just made good sense to me when I was thinking of what would be the easiest way to diffuse CO2. Plant growth is great and algae is practically nonexistent. I have val's growing out the top of the tank and sending out runners that I'm having to trim weekly along with swords, cabomba, water sprite, java ferns and an apon that are all very happy. My CO2 usually stays around 15-20 ppm and I'm following the EI method of fertilization and have 130 watts of PC.

So for me this is working well and I just wanted to relate my experience.


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## Bert H (Dec 15, 2003)

Regarding the diffusion method, I tried it for a while in a ten gallon which had previously had it injected into the hob filter. This was an established tank, no algae issues, healthy plants. I, personally, couldn't tell any difference using the same flow rate with the injection. Having said this, I am about to try to do this again, a little more scientifically correct this time by measuring pH (and subsequently CO2 levels via both ways). I just got some macranda which in the past has not been a happy camper in my tanks, and will use this as a 'test subject', so to speak. Will report back in about a month.


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## standoyo (Nov 6, 2005)

tom, 
assuming we don't fiddle with the co2 knob and just replace a normal co2 reactor with a mister method or your venturi reactor+p/head combo, you are saying you can get better growth?
this is to keep the amount of co2 dispensed equal.


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## plantbrain (Dec 15, 2003)

I'm not sure why the CO2 ppm needs to be the saem in tank A and tank B.

All you need is more or equal in one tank without the mist.

If the mist grows the plants better, then you have the answer.
PR is not the issue.
It'll play a role, but the O2 is not that high vs the higher O2 levels found in terrestrial plants. 

I cover PR in some BarrReport journals.
Madsen _et al _has a good research paper on the topic. 

Regards, 
Tom Barr


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## plantbrain (Dec 15, 2003)

Also, if the mist is not worjking for you, you might/likely have __other issues__ besides CO2.

That is why many think something does not work, they have several issues going on.

If you have low CO2 and dose PO4, you might think PO4 causes algae..........
I don't know the other issues you might or might not be having with the tank, CO2 alone is not everything, but it is a large part.

Regards, 
Tom Barr


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## standoyo (Nov 6, 2005)

hi tom,

not covering algae issue. no problem with that...[not unsolvable ones anyway]

just that trying to understand if i can save co2 with your suggested methods to achieve same growth rates as with normal co2 reactor...


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## standoyo (Nov 6, 2005)

hi tom,

there could be a way of testing this but quite impossible for me to have two co2 tanks valve that i can tweak exactly the same co2 output out for accurate comparison even if i can set the tanks side by side.


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## wapfish (Oct 14, 2005)

plantbrain said:


> PR is not the issue.
> It'll play a role, but the O2 is not that high vs the higher O2 levels found in terrestrial plants.


Pure O2 bubbles sitting directly over stomata represents a very high concentration indeed. You don't get that happening with terrestrial plants :icon_wink.


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## bastalker (Dec 8, 2004)

Can you achieve this effect by turning the Reactor upside down, placing an airstone inside of the reactor right by the outlet, and point the spray bar down to the bottom of the tank? The airstone would give the micro bubbles, and it wouldnt have time to disolve going from the outlet to the spraybar.

I might be out in left field with this though....


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## standoyo (Nov 6, 2005)

presuming you are feeding co2 thru the airstone, why would you need the reactor then? baffling


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## bastalker (Dec 8, 2004)

standoyo said:


> presuming you are feeding co2 thru the airstone, why would you need the reactor then? baffling


Well I was thinking along the lines of using what you already had, an not introducing anything else into the tank.


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## standoyo (Nov 6, 2005)

well, assuming you are talking about an internal co2 reactor... you can modify it yes as tom has mention somewhere in AQ or APC can't remember. don't know about the theory tom is putting out but i have his diy venturi p/head thing made and used it in my smaller 40g and even the moss pearl...

i have another 72g using a normal reactor and similarly the mosses pearl too...

i don't doubt tom's theories but it's one of those things. don't knock it if you haven't tried...so far not enough tanks to trybut i may convert two of my discus tanks to planted...shrimps and apistos...


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## wapfish (Oct 14, 2005)

Don't mean to get on a soapbox, but in post #129, Ogsy has gone and done what is perhaps the most basic control experiment for the entire CO2 mist phenomena and its importance should not be underestimated. He eliminated nearly all CO2 from the mist and found that it still enhanced growth, just as well as with CO2 present. Of course it's only one person's experiment, but it's an easy experiment to do. Is it really true that no one else has ever tried this? Or have I missed it somewhere? Tom, what about you? I fully expected you to dispute Ogsy's results, or at least present alternative results showing that you've tried substituting other gases and that only CO2 works. Have you really not tried this yet? It's hard to believe.

Why should one go to the bother of generating a CO2 mist when a limewood diffuser and an air pump would work as well? More importantly, if CO2 is not necessary for the mist effect to work, then that's saying something very important in terms of understanding what's going on in our tanks.


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## Betowess (Dec 9, 2004)

scolley said:


> Thanks Tom!
> 
> I'm afraid I'm in that group. I don't use a spray bar, so I suppose I'll have to finish my in-line rig (already bought the parts!) to try to accomplish the same thing - blowing small CO2 bubbles around the tank.
> 
> So, anyone else out there able to back this up? Tom seems pretty certain... sounds good to me. But is anyone here at PT ready to stand up and say "yeah - I tried it and it definately works!"


Steve, I just finished reading about 8 pages of this lengthy thread with some confusion and fascination. I'm glad you reopened it as I missed it the first time.

One thing to share. Some time back Wasser suggested to me to put a PVC outflow near the bottom of my 90. Its on one of two XP3s. It is "L" shaped with about 12 inches running across the back bottom of my tank ending with a 45 degree elbow pointing up and toward the back glass. (If you look at my sig. pic, it is the spray painted green PVC on the right. You can't see it on the bottom, but you can see the vertical part of the "L" shape. The other XP3 with Spraybar is on the left.) 

For some reason, my reactor was spitting out small gas bubbles out of the spraybar (on left side of the tank). So I moved the reactor, no small job, to this "L" shaped PVC outflow thinking that the bubbles will have longer to dissolve if introduced deeper into the tank. That has worked. Seems I have a lot of current between the two XP3s and also the much desired CO2 mini bubbles thanks to a flaw in the design of my reactor. I believe I used too small of diameter PVC (1.5 inch) and too short of a reactor to fully dissolve the CO2 (this reactor was dissolving all of the CO2 until I put a Hydor after it). I think the Hydor in-line heater slowed down the flow and turbulence resulting in the small CO2 bubbles. Also, when I moved the reactor I crammed about 3 or 4 oversized Bio balls in there to help. Now the bubbles are even smaller. And the plants back there probably trap alot of them floating up.

Now there are two reasons I'm sharing all this. One, is my tank is a major pearl about 8.5 hours out of 9.5 hours of photoperiod. And this happened more after I added the Hydor which changed the amount of CO2 dissolved in the tank. But I didn't notice the increased pearling until I moved the reactor to the XP3 with the L shaped PVC outflow on the bottom. That is because when the reactor was on the spraybar side, a lot of that gas was dispersed in the current at the top. The L. aromatica and L. repens and E. stellata near that "L" shaped bottom outflow grow like, well as fast as one can imagine. Also, this tank has a LOT of current that pushes those little CO2 micro bubbles all around! And very little algae save some glass dust. I don't dose PO4 and rarely nitrates due to all the food I feed my fish.

My theory is I have a lot of dissolved CO2 and a fair amount of micro CO2 floating around. Perhaps the best of both worlds? And maybe, with design mods and a hydor, an inline reactor can be designed to achieve this. The funny thing is about two days ago I just finished a new reactor with a larger diameter to fix this "problem". Then the next day I started reading this thread. Now I have an extra reactor for the next tank. Because I'm going to leave well enough alone after reading this long long thread. regards, bob


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## standoyo (Nov 6, 2005)

wapfish said:


> Don't mean to get on a soapbox, but in post #129, Ogsy has gone and done what is perhaps the most basic control experiment for the entire CO2 mist phenomena ...


oqsy's experiment[we call it bump on the head with a durian fruit-by chance, a windfall]:lol:...is not what i had in mind.
his discovery only proves that with good flow coverage and 'flooding' the tank with co2 at 50 ppm gives great growth with hard to grow species doing well.

i'm trying to save on co2[save $$$], get decent growth rates...

besides hating WC, i hate dosing like a robot. i hate routine, i hate paying for co2 which i know is wasted...
knowing there's a wc at the end of the week, trimming, dosing etc just puts me off. it's like 3-4 hrs of my life is blocked out everyweek. there's more to life that WC dosing etc.


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## wapfish (Oct 14, 2005)

standoyo said:


> oqsy's experiment[we call it bump on the head with a durian fruit-by chance, a windfall]:lol:...is not what i had in mind.
> his discovery only proves that with good flow coverage and 'flooding' the tank with co2 at 50 ppm gives great growth with hard to grow species doing well


:icon_lol: durian on the head is a pretty funny image.

I understand what you're saying. On the other hand, ogsy did make the point that the only difference he could identify that might be responsible for the great growth was misting air. The thing for him to do is to turn off the air mist, leave CO2 levels, flow around the tank unchanged, etc, and see if the superior growth subsides or not. If growth isn't dependent on the mist, then it's obviously due to something else. End of story. However, if growth is dependent on an air mist, and is then recovered when the mist is turned back on, then whoa, wait a minute! It would be so weird if CO2 isn't actually necessary for the "mist" effect, but it's a very basic assumption everyone is making. Pretty obvious the world is flat, right?

In science you absolutely have to do the control experiments. The most basic one I can think of is to show that yes, the gas has to be CO2 for the mist effect to work. Since Tom Barr is the major promoter of the mist effect and does all kinds of experiments with aquaria, it's to be expected that he'd simply tell us that yes, he's checked, and the gas has to be CO2 or it doesn't work. This is a really simple thing. If that statement is never made and if that assumption is never confirmed by anyone, then the ball game is wide open and one has to give results such as ogsy's greater respect until proven otherwise. His observations could be the tip of the iceberg as easily as a durian on the head.

I know it sounds crazy to suggest that the mist doesn't have to be CO2, but rest assured that if that were ever shown to be the case, an explanation would be found, a very good explanation.


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## SCMurphy (Oct 21, 2003)

You guys coming late to the party really need to read the other three threads.

http://www.plantedtank.net/forums/g...ubility-experiment-photos-video-evidence.html
http://www.plantedtank.net/forums/g...iscussion/21609-co2-revelations-part-2-a.html
http://www.plantedtank.net/forums/general-planted-tank-discussion/22617-co2-mist-report.html


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## standoyo (Nov 6, 2005)

glad you find it funny...

well i don't have many stem plants to try Oqsy's discovery. otherwise i can't imagine waiting for a crypt to show results!

all i know is that when circulation is good. misting or not my plants pearl like crazy in med bright light...


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## standoyo (Nov 6, 2005)

SCMurphy said:


> You guys coming late to the party really need to read the other three threads.
> 
> http://www.plantedtank.net/forums/g...ubility-experiment-photos-video-evidence.html
> http://www.plantedtank.net/forums/g...iscussion/21609-co2-revelations-part-2-a.html
> http://www.plantedtank.net/forums/general-planted-tank-discussion/22617-co2-mist-report.html


double oops...just on the the second link...nail biting...thanks for the links!

stan


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## wapfish (Oct 14, 2005)

SCMurphy said:


> You guys coming late to the party really need to read the other three threads.
> 
> http://www.plantedtank.net/forums/g...ubility-experiment-photos-video-evidence.html
> http://www.plantedtank.net/forums/g...iscussion/21609-co2-revelations-part-2-a.html
> http://www.plantedtank.net/forums/general-planted-tank-discussion/22617-co2-mist-report.html



I'm familiar with those threads, but I don't recall anyone ever explicitly showing that the gas you mist with has to be CO2. Is it buried in there somewhere and I missed it?


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## unirdna (Jan 22, 2004)

wapfish said:


> I'm familiar with those threads, but I don't recall anyone ever explicitly showing that the gas you mist with has to be CO2. Is it buried in there somewhere and I missed it?


Nope, that was never shown. No one ever tried to simply 'mist' air. I think you make a very good point; Tom's experiment never had a control tank. This experiment (blind, of course) is very necessary.

Experimental:
Mist CO2 bubbles in front of a source of current.

Control:
Inject CO2 via a reactor (total dissolve), and mist air in front of a source of current.

It would be necessary to maintain both tanks at the same CO2 ppm. I'd say to simply use the same bubble rate, but I would suspect that a reactor is more efficient; so, dual pH controllers may be necessary. Same plant assortment and biomass. Same substrate. Water parameters, Etc etc.


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## wapfish (Oct 14, 2005)

unirdna said:


> Nope, that was never shown. No one ever tried to simply 'mist' air. I think you make a very good point; Tom's experiment never had a control tank. This experiment (blind, of course) is very necessary.
> 
> Experimental:
> Mist CO2 bubbles in front of a source of current.
> ...


Exactly.

Ogsy (and anyone else that's interested) can approximate the idea of a control tank (best way to do it) by going back and forth between air, CO2, and no mist and getting reproducible results each time. If an air mist were to work, which is the interesting result, it probably wouldn't matter whether the dissolved CO2 is kept absolutely constant by controllers. It would probably be enough to make sure the dissoved CO2 source (reactor or whatnot) is left unchanged (also flow, lighting, etc). Ogsy's result was particularly intriguing because dissolved CO2 should have been decreased, if anything, by the air misting, yet he observed better growth.


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## Betowess (Dec 9, 2004)

SCMurphy said:


> You guys coming late to the party really need to read the other three threads.
> 
> http://www.plantedtank.net/forums/g...ubility-experiment-photos-video-evidence.html
> http://www.plantedtank.net/forums/g...iscussion/21609-co2-revelations-part-2-a.html
> http://www.plantedtank.net/forums/general-planted-tank-discussion/22617-co2-mist-report.html


oh jees, there's alot more reading to do. This may take a few days:icon_roll Thanks Sean. bob


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## Oqsy (Jul 3, 2004)

let me clarify a few things here, and let me also say once again this could quite likely be a fluke that i'm observing, something else that happened to fall in place at the same time coincidentally, etc...

clarification #1 *circulation*: I already had the powerheads running in the tank off and on for some time *without* the air bubbles being added. the flow was being aided WITHOUT any extra bubbles and I did not see the sudden improvement like I have WITH the air bubbles. 

clarification #2 *CO2 concentration*: currently my tank reads 
kH 90ppm, pH 6.6 ~ 38ppm CO2 with the bubbles on. This is the same CO2 bubble rate I was using to achieve 50 ppm CO2 WITHOUT the bubbles. so, I'm losing about 12ppm CO2 due to aeration, but 38ppm is still plenty of CO2 to do the job... 

Now, I didn't bring any of this information into this thread for any reason other than discussion. If anyone can shoot it down, that's great, one less variable out there to worry about. If not, that still doesn't mean that there's anything to it... planted tanks are complex little systems, especially once you start pumping in tons of light, co2, ferts, etc... I am simply sharing what has been an interesting experience for me 

Oqsy

*edited on 2-28-06...*image and example of "l. aromatica" removed because I realized after looking at the pics for a few minutes that the plant i thought was aromatica couldn't be, because it's leaves are thin and straight with no serration on the edges as is typical of aromatica. so my example was moot. different plant, different results... not exactly an example i want to use since it doesn't prove anything except this other plant likes my tank more than aromatica. (anyone know a plant that looks like aromatica with the purple stems, but the leaves are thinner and straight? a ludwigia perhaps? cuba / pantanal? does p. stellata have a purple stem?) anyway, i apologize to anyone who read the post before and feels "cheated"... it was not intentional (i'm no plant expert, as anyone on this board who has answered my questions can tell you), and I still plan on posting a pic of ludwigia repens, brevipes, and glandulosa in the current setup (growth and color like nothing i've ever posted before). so there you go...


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## John S (Feb 27, 2004)

ok i was wondering if i put the co2 line in a powerhead could i get the same affects???? or would i have to much water flow


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## plantbrain (Dec 15, 2003)

unirdna said:


> It would be necessary to maintain both tanks at the same CO2 ppm.


No, it does not need to be the same, if the CO2ppm is higher in the non mist tank and you get higher DO levels in the mist tank with the lower CO2ppm, then you know the difference in growth which is a direct function of O2 production, is due entirely to the mist.

You would expect the lower CO2ppm to produce lower O2.
If it produced more O2, then the extra O2 had to come from somewhere.......

Say I had a tank with 25ppm(mist) and another with 35ppm(no mist).
If the mist tank had higher O2 readings, then the mist would have something to do with it.

You also see a nice gradation decreasing away from a CO2 mist source on the plants. Closer to the source: more misting. Farther away, less.
The CO2 measured in the tank's water is the same.

Regards, 
Tom Barr


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## scolley (Apr 4, 2004)

In another thread, here, I've been dealing with trying to employ Tom's idea in a tank that does all water treatment in-line, in order to get stuff out of the tank. But because I am anxious to see if this really works, I broke a cardinal rule for me... I put an Azoo ceramic diffuser, blowing CO2 micro-bubbles, in front of one of my outflows. Only temporarily, just to run a test. This did not alter how I get CO2 into the water, I just ran a "T" off my pressurized system to run CO2 to the Azoo, as well as the normal CO2 to my DIY in-line diffuser.

Unfortunately this weekend I also removed some wood from my tank, and slightly tweaked my fert regimen. But I don't mind saying that for the last two days since I did this I've had this I've had pearling _insanity _in my tank. Granted multiple things have changed; wood removal, fert tweak, and the CO2 micro-bubbles - not good for a test.

But with these encouraging results, I think I'm going to leave everything _perfectly _stable for a month. But I'm going to alternate weeks - one week blowing CO2 out of the diffuser - one week without - and then repeat.

Hopefully it will be a good test. All I've got to do to alternate between the two conditions (micro-bubbles and no micro-bubbles) is turning an air valve on or off. Same circulation, same SMS122 managed level of dissolved CO2 in the tank under both conditions. So we'll see.

But I can certainly say this... I have _never _seen pearling like this in one of my tanks. Will report more in a month.


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## unirdna (Jan 22, 2004)

plantbrain said:


> No, it does not need to be the same, if the CO2ppm is higher in the non mist tank and you get higher DO levels in the mist tank with the lower CO2ppm, then you know the difference in growth which is a direct function of O2 production, is due entirely to the mist.


Tom, I think you missed an important aspect of this proposed experiment - both tanks would have mist. One, CO2 mist. The other, air (N2,O2 mist). Since we would mist O2 into the control tank, we couldn't use a DO meter to interpret which tank is more photosythetically active. 

Example:
If both tanks read the same O2, would we conclude that CO2 misting has no effect on photosynthesis? Or would we conclude that misting air (O2) increased the O2 in the control tank, so, in fact CO2 misting _does_ increase photosynthesis?

See what I mean? You can't be adding the thing (O2) you're testing :icon_conf. Observation and/or plant mass measurement is the only true way to analyze the "double mist" experiment.


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## Betowess (Dec 9, 2004)

scolley said:


> I put an Azoo ceramic diffuser, blowing CO2 micro-bubbles, in front of one of my outflows. Only temporarily, just to run a test. This did not alter how I get CO2 into the water, I just ran a "T" off my pressurized system to run CO2 to the Azoo, as well as the normal CO2 to my DIY in-line diffuser.
> ... for the last two days since I did this I've had this I've had pearling _insanity _in my tank.
> But with these encouraging results, I think I'm going to leave everything _perfectly _stable for a month. But I'm going to alternate weeks - one week blowing CO2 out of the diffuser - one week without - and then repeat.
> 
> ...



Thats great. I think we'll finally have some more verification. And it sounds easy to add on. Good job Steve!:thumbsup:


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## Glouglou (Feb 14, 2006)

*Loud Thinking!*

:icon_roll 
I have a 33 gal with pressurize co2, solenoid and timer start 1 hour before day and shutoff 1 hour before night.

My “reactor” is the ladder of a yeast co2 generator from Hagen.
Output is something like one bubble a second.
all of the bubble disappear before reaching the top, totally dissolve.

I try to keep a good water movement to spread the co2 charge water.

Work very good! Planted start to look good, pearling 1/2 to 1 hour after light on (timer)

But I have a doubt above the quantity of CO2 in the Water. Using peat in filtration the relation KH/PH is not reliable. I used the Krause method, where I find that my ultimate PH is around 6.5.
I’m around 7 now, I will pump up the volume on the CO2 and try more peat to lower the ph. 
I keep my kh around 20 to 30 mg/l

I probably try to make a DIY reactor to have a more efficient used of the CO2
and at the same time add water movement to reduce the Prandtl boundary.

OUF!


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## wapfish (Oct 14, 2005)

The correct way to do it is to run two tanks, one with N2 mist (not O2, not air) and the other with CO2 mist, both with controllers to keep dissolved CO2 constant, all other variables (light, plants, etc) the same, and to monitor relative increases in plant biomass over time. Straightforward and direct. Photographs would probably suffice if the effect were dramatic.

Using DO is as an indicator for photosynthesis is not a good idea. There are just too many potential complications (eg supersaturation). If oxygen is measured at all, it should be total oxygen coming off the tank.

Lastly, quick and dirty is to just mist CO2 or air (better N2) in front of a powerhead with CO2 being added separately via reactor or whatever and compare relative growth. If air works as well as CO2 the result will be significant, since dissolved CO2 will be lower when misting air. Of course the only reason to try this less rigorous way is because it's easy and someone already said they did it  .


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## gingee (Feb 23, 2006)

*Which way to go?*

Hmm.

I'm just about to set up a tank and was looking through here for the best diffuser to buy (I didn't want a reactor to slow down the flow rate as I will be running UV already).

So why shouldn't I just buy the Red Sea mini powerhead and be done with it. surely if i have a spray bar across the surface from left to right and then the CO2 powerhead near the bottom flowing right to left then I will get optimum circulation of CO2 in the tank (as well as helping to eliminate dead spots) .

Ginge


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## Betowess (Dec 9, 2004)

Its been a little while now...So has anyone done a test comparison with the ceramic mist method as opposed to a traditional inline reactor yet. I'm not talking about a hard scientific method with controls etc., but just a simple hobbyist style of one week with the disc vs. another week with a reactor (in the same tank) and visually noticing and or comparing which method has better or worse plant growth, pearling etc.


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## plantbrain (Dec 15, 2003)

unirdna said:


> Tom, I think you missed an important aspect of this proposed experiment - both tanks would have mist. One, CO2 mist. The other, air (N2,O2 mist).


Air has CO2 also.



> Since we would mist O2 into the control tank, we couldn't use a DO meter to interpret which tank is more photosythetically active.
> 
> Example:
> If both tanks read the same O2, would we conclude that CO2 misting has no effect on photosynthesis? Or would we conclude that misting air (O2) increased the O2 in the control tank, so, in fact CO2 misting _does_ increase photosynthesis?


Yes, the O2 levels are the same=> then you get the same plant production.
Remember that O2 is lost like CO2 from higher flow rates etc, these need to be similar as best we can.



> See what I mean? You can't be adding the thing (O2) you're testing :icon_conf. Observation and/or plant mass measurement is the only true way to analyze the "double mist" experiment.


What? I did not propose that I added O2 here. Just measure it.
I simply said you do not need to measure the exact same CO2ppm in the mist vs the non mist tank.

As long as the non mist tank has as much or more CO2 ppm dissolved, as the mist tank, then when you measure the O2 levels ppm, if the mist tank has a higher O2 level, then the difference in O2 is due to the gas phase affect.

You can see this affect in most any tank near the out flow of a CO2 reactor/mist stone etc on the plants. 


Regards, 
Tom Barr


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## Plantasia (Jan 11, 2006)

BSS said:


> Wow! I'm glad I'm not the only one that is confused about all of this. I've never used a venturi, and a diffuser sounds like it should be more high tech than it really is. I did a fair amount of reading and thinking about this one last night, so let me share my current thoughts.
> 
> First, I think the venturi stuff and all the mods to external reactors is really just confusing this topic. In Tom's first post, he talks about "I'd suggested..." meaning to me that he used to suggest how to make reactors better. But, I don't think this is really germaine to this discussion.
> 
> IMO, this whole 'new' idea is to just turn the CO2 into small, pure CO2 bubbles and then make sure it is in the filter output stream so that it gets pushed around the tank. Oqsy basically did this by feeding his CO2 line into the inbound side of a powerhead, so it chopped up the bubbles (a 'high-tech' diffusor :wink: ). He then used some modified tubing to help disperse things a bit better.


THANK YOU. As a newbie who's never used a reactor either I appreciate the simplified summary. Does this only work with pressurized CO2 though? I use the Hagen canister/ladder currently. Would I just get rid of the ladder, hook up the CO2 line to a powerhead intake (I have a Rio 50 that I haven't installed yet). Or will the diffuser disc work okay with DIY C02? I DID read through this entire thread (and have bookmarked it!), but am still fairly new to all this so sorry if my questions are stupid and/or redundant.


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## esarkipato (Jul 19, 2005)

I'm afraid a new subject/experiment has started being discussed now, Tom. Folks are suggesting that instead of testing co2 microbubbles versus total diffusion, we should test co2 versus o2 microbubbles. If the o2 microbubbles increase growth as much as the co2 bubbles, that proves your original theory (sort of) but also confirms that it's really the reduction of the prandtl boundary possibly combined with knocking off the pearling that increases growth, not the fact that it's co2. Am I making any sense?

But I think first we should establish, once and for all, whether or not co2 microbubbles really do increase growth. I personally am convinced due to my own experiments, so the new co2 versus o2 microbubble experiment interests me thoroughly (new thread . . . . .?).


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## John S (Feb 27, 2004)

ive been doing it for like 2 weeks now and my plants are really taken off all my stem plants grow those white roots about 3 inches a day


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## Betowess (Dec 9, 2004)

*John S*, You've been doing what? Using a diffusor with CO2 or a diffusor with O2? And have you compared that to a traditional reactor or what? TIA

*Eskarpito*, I for one am still curious if anyone has done a comp between a traditional pressurized "Hoff/Rex" style reactor vs. pressurized ceramic diffusor? I wasn't aware if this question has been resolved yet. Maybe someone could pipe in "in plain english. I don't think I understand what Tom is saying.


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## jhj (Jan 31, 2006)

*Rex Reactor as a source of fine CO2 bubbles*

I have read threads on the 'Rex Reactor' and heard many people complain of small bubbles coming out of spraybars of their canister filters; to reduce the flow of bubbles they tilted the reactor or built one with a larger diameter to dissolve the CO2 better and reduce the bubbles.

It seems to me that what Tom is suggesting can also be accomplished with a Rex Reactor where the CO2 is not fuly dissolved and tiny bubbles escape from the Spray bar which are then transported to the differnt sides of the tank with the current.

What do you guys think? Am I wrong, did I miss the point


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## Betowess (Dec 9, 2004)

jhj said:


> I have read threads on the 'Rex Reactor' and heard many people complain of small bubbles coming out of spraybars of their canister filters; to reduce the flow of bubbles they tilted the reactor or built one with a larger diameter to dissolve the CO2 better and reduce the bubbles.
> 
> It seems to me that what Tom is suggesting can also be accomplished with a Rex Reactor where the CO2 is not fuly dissolved and tiny bubbles escape from the Spray bar which are then transported to the differnt sides of the tank with the current.
> 
> What do you guys think? Am I wrong, did I miss the point


That is some solid, creative thinking... I'm impressed.:thumbsup: 

I actually had that happen to a degree, because when I added some inline Hydor heaters, my flow slowed down enough in my reactor to cause CO2 bubbles to come out of the outflow, which was first a spraybar, then changed over to my other filter which had a DIY PVC output at the bottom of the tank. I moved it to the other filter with a low output at substrate level to give the CO2 more time to dissolve as it rose from the bottom to the top. They were pretty small bubbles... but,

I don't think they were as small of bubbles as are being discussed here. Mine were small, but by no means "micro" sized. That being said, one could make that happen, because I stumbled upon it. And they were usually all dissolved by the time they reached the top, or were certainly absorbed in time if caught on the underside of a plant leaf.

I also got a lot of either O2, CO2 or both flushing and burbing and I very recently installed a new, larger diameter DIY reactor. I'm not sure what caused the burp flushing. But my cannister's flushing noises have ceased with this larger reactor. They sounded like something from a submarine wooosh and I kind of miss their intermitant punctuations.


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## esarkipato (Jul 19, 2005)

jhj, that is exactly (sort of) what happened to me. 

My first method of dissolving my pressurized co2 was an in-tank "rex-style" reactor, a picture of it is here. It's job was basically to completely dissolve the co2, and it did a pretty good job. Got moderate pearling, some of the time.

Now I set up a "ceramic diffuser" to create microbubbles. I didn't put this under my filter spraybar, but rather let the bubbles enter the filter through the inlet. They travel through, some being dissolved, some not. I still get many microbubbles shooting out my spraybar, and flying around the tank.

The pearling now is far better than previously .. . . . for pretty much all of the species. Fertilizing/lighting has remained constant.


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## bonklers (Oct 17, 2005)

esarkipato said:


> Now I set up a "ceramic diffuser" to create microbubbles. I didn't put this under my filter spraybar, but rather let the bubbles enter the filter through the inlet. They travel through, some being dissolved, some not. I still get many microbubbles shooting out my spraybar, and flying around the tank.


esarkipato, did you got better result from the new setup with "ceramic diffusor ->filter inlet", than with "ceramic diffusor ->filter outlet"? I'm running my CO2 line right through the powerhead inlet, the motor crushes the bubbles to very little ones. Now I'm wondering if it's worth it to buy a ceramic diffusor that goes straight into the powerhead inlet.


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## esarkipato (Jul 19, 2005)

Yea, I'd say better results. I have a hard time keep the bubbles underwater when I put the diffuser right under the outlet. I guess the micro bubbles are even more micro once they've made it through the canister. 

Not sure if the ceramic diffuser would benefit you all too much, but if you are unsatisfied with current c2 methods at $15 it's worth a shot!


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## jade_dragon71 (Dec 2, 2005)

I've been watching this thread with great interest, in fact, this was the method my DH and I decided to go with way before we got our CO2 stuff.

I can offer my humble, limited observations with this so far, since we have a sump set-up that caused microbubbles from the start until Tim backed off the flow enough to rid the outflow of it. During this "tweaking" time, there was no pearling at all. (But lots-o-little-bubbles!) Today we got our CO2 hooked up. (A wooden airstone is fixed below the intake to the pump, so that the pump will diffuse the CO2 into tiny bubbles that blow out with the outflow.) In 15 minutes time of hooking this up, the plants started pearling madly!!! 

This is in no way a "long term" observation just yet. We did a 50% water change today after we observed this since I dose K, P, and iron heavily. (No need to dose P since the reading in my week old tank is already 5 ppm- we have it present in our tap water.) Of course, there was heavy water change pearling, but I'm not making any judgement with that since that's always happened in my tanks without CO2 injection. We have it set to 30 ppm now, and we're going to run it all night to see how it affects the fish before we decide if we're going to put it on the timer with the lights (whenever that gets here). 

I'll post the progress on this later, too....


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