# Is air stone needed?



## Jaseduck

*no*

No its not need all air stones do is to circulate the water


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## mattinmd

Needed, no. Beneficial, maybe.

Either surface agitation or airstones will aerate the water. If you have a lot of surface agitation, you are probably already well aerated and airstones will probably only help move water around.

I personally like to use them to avoid dead spots in corners behind ornamnets, etc. The extra aeration is probably more than I need, but it doesn't hurt. That said, I'm a bit old-school and airstones are certainly not in-style anymore. Circulation pumps are more the current style, as you can aim them anywhere.


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## Django

This can be a contentious question because it deals with carbon dioxide, a major nutrient (C) in the planted aquarium, surface gas exchange, and associated differences in CO2 in high tech and low tech aquaria. I still don't understand Dalton's Theory of Partial Pressures of Gas.

All I know is if we isolate the dissolved CO2 level and compare it to the atmospheric level of the gas, when the dissolved pressure is higher than the atmospheric pressure, like at night, the CO2 will try to get out through surface gas exchange - this we want to avoid, and retain the CO2. If, however, the dissolved level of CO2 is less than atmospheric, as during photosynthesis during the day, then atmospheric CO2 is trying to pass through the water surface and join their understaffed compadre molecules. This would happen faster with an airstone.

Water movement throughout the tank allows these processes to both happen faster. So does water surface agitation, as by airstone. But CO2 is only used up, by plants, during photosynthesis, and not during the night, when it accumulates in the water. If you use an airstone, you gain some CO2 during photosynthesis but lose some dissolved CO2 at night.

This applies to low tech tanks. In high tech tanks an airstone would lose some of the pressurized CO2 from the water, a specialized case of daytime CO2 gas exchange.


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## brandon429

I don't understand gas laws either. But I'm under the impression at no time will an airstone boost co2, only off gass it always making the aquarium concentration lower and never higher unless the room has an abnormally high level of co2 

I wish we could get links to finalize this I don't have any. Thats just what I get from reading online posts.


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## Django

I googled around for links but all I found was about injected CO2. They do say that an airstone will degass their CO2, which sort of underlines my point.

I guess that people should forget about comparisons with the atmospheric concentration and accept that airstones will degass CO2, which is necessary for plants. For adequate oxygenation, move the water so it is exposed to the surface.


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## Diana

Air stone increases water circulation. 
The rising bubbles move the water upward, too. 
At the surface the bubbles pop, causing agitation in the water. 
This increases the water surface area. 

Where water is in contact with the air it will exchange gases. All gases. We are mostly concerned with CO2 and O2. (minor note: the air is mostly nitrogen, and this gas also is being exchanged at the water surface, but neither fish nor plants use the N gas in the water)
Exchange means gases can go both ways. 
Which ever (air or water) is higher in a particular gas will donate some of that gas to the other. 
Which ever is lower in a particular gas will gain some of that gas from the other. 

In an aquarium with just decomposing matter, CO2 rises, oxygen gets used up. 
In an aquarium with decomposing matter and animals, (Fish only or just a few plants) CO2 rises, oxygen gets used up. 
In an aquarium with plenty of plants the CO2 will follow a daily cycle, following the light. Plants can remove all the CO2 from the water through the day, but they add CO2 during the night. Some of this nighttime CO2 leaves the tank when it reaches the surface, but a lot of it lingers until the morning light starts the plants photosynthesizing, and the plants remove it. With plants, fish and microorganisms all using oxygen through the night the oxygen can get used up faster than water circulation can replace it. 
A heavily planted tank with reasonable to low light and fertilizers can use all the CO2 that the fish and decomposing materials and gas exchange are adding to the water, but are not really deficient, they are growing slower because of the low light. This is the basis of the Walstad type of tank. 
In a tank with high light the plants are very deficient in CO2 so people add pressurized CO2. 

Now, back to the airstone. 
An airstone can ADD CO2 to the tank, if the water is low in CO2. The increased circulation and surface area will help the water take in more CO2 from the air. 

An airstone can REMOVE CO2 from the tank, if the tank has more CO2 than the air. The increased circulation and surface area will expose more CO2 to the air and it will leave.

So, to use or not to use an airstone:

1) If the fish are gasping in the morning RUN AN AIRSTONE. The fish are using up too much oxygen through the night, and the airstone, run through the night, will help add oxygen to the water because of the increased circulation and surface action. This will also drive off CO2, but since the plants are not using it in the dark this is not a problem. The air stone can be on a timer so it runs from lights out to perhaps an hour before lights on. In that last hour the tank will be accumulating CO2 to help the plants. Monitor it to make sure the fish are still OK. 

2) If you are adding pressurized CO2 or CO2 from a DIY/yeast-sugar system you may run into situation 1) but do not run the airstone in the day. It can drive off the CO2 that you are adding from either system. 

3) If the fish are not gasping then I would not waste the power running an air stone. I have enough circulation from filters and power heads that I do not need more circulation from an air pump.


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## NJAquaBarren

The value of an air stone is just water movement. It really doesn't add significant O2 to the water. Surface agitation and good circulation in the rank are what is needed. There are better devices to enhance agitation and circulation. 

One drawback of air stones is that the bubbles burst and splash on a wide area. This will leave dried minerals and proteins on nearby parts of the tank, lights and components. A nuisance to clean. 

If you need to augment, better to use a powerhead of some form


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## nicuz

Ok so we all pretty much agree the air stone moves water but a power head is a much better alternative. The problem is that my tank is only 10 gallons and I am concerned a power head is too big for my tank's size (it will ruin the aspect). Are there any power heads small enough for a 10G?


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## snail

We get hot summers where I live and I find an airstone very useful when the temps get so high that that the fish are struggling.


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## mattinmd

In a 10g you could probably get sufficient agitation and circulation out of your filtration pump, particularly if you are using a HOB filter that ends up "dropping" the water a half-inch or so into the water.


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## NJAquaBarren

nicuz said:


> Ok so we all pretty much agree the air stone moves water but a power head is a much better alternative. The problem is that my tank is only 10 gallons and I am concerned a power head is too big for my tank's size (it will ruin the aspect). Are there any power heads small enough for a 10G?


Yes, there are. Search your favorite stores for nano, or pico pumps. 


Sent from my iPad using Tapatalk HD


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## Raymond S.

You have not stated what kind of filter you intend to use in this tank.
The filter may provide enough O2 via circulation. You also have not stated if injected CO2(or DIY CO2) will be used.
Some filters can be placed on a tank so that they have very good circulation by simply putting it on the end instead of the back of the tank.


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## Diana

About the smallest pumps I have found are the ones for table-top fountains. Less than 2" cube, can move about 60 gph. I use one in a 10 gallon to run a waterfall. LOTS of water movement! 

If you get a filter such as the Aquaclear 20 that is highly likely enough water movement for a 10 gallon.


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## Django

For people who are running a filter and are getting enough circulation in the planted tank, I would recommend not running an airstone at night, unless, of course, you find the fish gasping. I want to hang on to every molecule of CO2 that I can so that it can help the plants the next day. There is so little CO2 in non-injected tanks to begin with.


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## Raymond S.

I believe that Diana just explained that in a non injected CO2 tank using an air stone increases the amount of CO2 by bringing more water to the surface where it can absorbe more CO2. If it has no injected CO2 then the normal amount that it can absorb will be depleted during the day when the plants are using it. Only natural abssorbing through contact/w the atmosphere will raise it back to the normal level and circulation plays a major role in this process. And if the tank has fish in it this is one more thing that has to be compensated for. So using an air stone in a non injected CO2 tank can ONLY help this process and can not deplete the amount of CO2 in the water.


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## Daximus

Raymond S. said:


> I believe that Diana just explained that in a non injected CO2 tank using an air stone increases the amount of CO2 by bringing more water to the surface where it can absorbe more CO2. If it has no injected CO2 then the normal amount that it can absorb will be depleted during the day when the plants are using it. Only natural abssorbing through contact/w the atmosphere will raise it back to the normal level and circulation plays a major role in this process. And if the tank has fish in it this is one more thing that has to be compensated for. So using an air stone in a non injected CO2 tank can ONLY help this process and can not deplete the amount of CO2 in the water.


x2!


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## Django

Raymond S. said:


> I believe that Diana just explained that in a non injected CO2 tank using an air stone increases the amount of CO2 by bringing more water to the surface where it can absorbe more CO2. If it has no injected CO2 then the normal amount that it can absorb will be depleted during the day when the plants are using it. Only natural abssorbing through contact/w the atmosphere will raise it back to the normal level and circulation plays a major role in this process. And if the tank has fish in it this is one more thing that has to be compensated for. So using an air stone in a non injected CO2 tank can ONLY help this process and can not deplete the amount of CO2 in the water.


Raymond,

CO2 will be dissolved in the water when there is less in the water than in the air. Conversely, if the water has more CO2, some will escape through the surface. An airstone facilitates gas transfer each way.

At night, CO2 is building up from organisms' respiration from a low level at the point that the lights go out. We want this CO2 to stay in the water to be used during the next day when photosynthesis uses up CO2. Honestly, I don't know how many ppm of CO2 we're dealing with, as I recall around three units that are being used to quantify dissolved CO2. By using injection, which we in the Low Tech Forum don't like to do, you can dissolve up to 30 units of CO2.

It is not true that "Only natural abssorbing through contact/w the atmosphere will raise it back to the normal level." There's CO2 released by respiration of any organism in the tank, except for some odd bacteria.

Steven


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## brandon429

Just to be on point about one thing, I agree mostly with what you wrote Diana except one 

not getting links perpetuates my misunderstanding. I looked but can't find. Reading up on Henry's law seemed to help but not clear yet. 

Link it pls I can't find links that support the notion so I press on 

I'm claiming that you cannot use an airstone to increase co2 in a tank if the air is pulled from a room of normal co2 levels. No condition in the tank creates a draw or attraction for co2, only a source and then it wants to escape much faster than oxygen at our temps, water doesn't retain it well at all and it wants to leave. If you pump standard outside air not elevated in any way you can never increase the co2 over any period of time in a tank of clear water, the offgassing will outpace it and no net co2 from usual air percentages will accumulate. 

Until linkage, I'm claiming typical airstones (where the room does not have elevated co2 levels) always off gas and never add co2 gas in an accumulative manner, regardless of the tanks natural co2 levels. So we have a rather opposing view, can't wait to get finality on this. I find gas dynamics very tricky hard stuff.


Read around at aquatic-Eco.com they are tops in the industry for gassing lakes etc they are co2 masters check em out 

Not once there am I seeing links that reverse my thinking, they all support it but I really want that concept tested and re explained if wrong. I really care greatly about at least solidifying the notion we have to pump in elevated levels of co2 to get any form of sustenance above pre air co2 levels for any aquarium.


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## Django

Here is one link on Dalton's Law - read the first sentence in the paragraph about 1/4 the way down.

http://books.google.com/books?id=rKzsij-FCI0C&pg=PA15&lpg=PA15&dq=carbon+dioxide+freshwater+equilibrium&source=bl&ots=4_Aaq7VK6C&sig=B9D1V8ffTs_Kg_j-PWtVgqAIJM0&hl=en&sa=X&ei=qx47VOD0CLDfsAT3l4GQCA&ved=0CC8Q6AEwAg


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## Raymond S.

I believe if I may, that you are overlooking one major point.
After a day of plant growth the level of CO2 in tank water is far below what it normally is. There is a normal level. If the water has a level of CO2 that is below normal, any contact with air which contains a normal level of it will cause the water to absorb some of the CO2 till the level is equal to that in the media which it is in contact with.
Therefor if after a day of plant growth a tanks CO2 level is much lower than normal. In this case a transfer will occur upon contact with a media which has a higher level of it.


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## Django

This is an explanation of the equilibrium of CO2 in solution in water and CO2 in the atmosphere. However, there are also other sources of CO2 in the tank - animal and plant, that are releasing CO2 into the water 24/7. It is just that at night nothing is taking in CO2 and there's time to build up. I wonder how permeable the water surface is, i.e. how long it takes for a molecule of CO2 to get through, or for the equilibrium to equalize. Maybe it depends on how skewed the equilibrium is.


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## Raymond S.

I can easilly see those things being big factors in the speed of transfer.
If fish are there they also will contribute to that level which it eventually gets raised to. In a previous statement I made I said "the only way it gets into the water is by absorbing from the air naturally" and when I said that I was not taking into consideration the fish in the tank and their respiration.
But allow me to present a picture. A tank is a closed system. We really don't know all the sources of CO2 in a stream or river for example.
But if the transfer of CO2 from the air to the water were seriously ineffective, then plants in a tank would eventually completely drain all of the CO2 from the tank water and the plants would die.
So this transfer must be efficient enough to reestablish a normal level of CO2 overnight. Keep in mind that some of the tanks out there have plants and no fish. So all of the CO2 in those tanks is absorbed overnight to at least a reasonable level of it.


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## Django

IMO, if you're talking about a working fish tank, you can't neglect the biology. Bacteria are very numerous and they release CO2 during respiration. So do plants. Actually, so do we, although it just goes into the atmosphere, to be dissolved in aquaria all over the world.

A tank of distilled water at 7pH and constant air pressure would have a known quantity of CO2 which would be at it's equilibrium value, it's true. The amount would be dictated by the equilibrium equation. If there was too much CO2, some would leave until it reached equilibrium. If there was too little... well, you know. We know this. Replenishing the CO2 lost through plant photosynthesis must be a combination of atmospheric and in-tank biological factors. It is also my understanding that the biological factors and the atmospheric factor can go from a level below equilibrium to a level above equilibrium overnight.


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## brandon429

Read that link before, it isn't saying things about plant respiration like we are, still not clear. its not talking about active removal of co2 (surface boil escape) at a far greater rate than we are adding it via atmospheric air. 

Show me where offgassing doesn't outpace then I'll be clear. Aquatic-Eco.com talking points is where I'm getting my notions, their writing is specifically about aquarium dynamics and co2 and they say that offgas is the net effect of water boil and not co2 addition 

Don't give up this is no argument. I'm asking for aquarium specific links that talk about de stratification and physical actions of water upwelling when pumping in standard balance atmospheric co2 that cause a retention in co2 

Everything on their site is the study of water boiling/de stratification to decrease it. As they pump in atmospheric co2 balanced air.

Bump:


Django said:


> IMO, if you're talking about a working fish tank, you can't neglect the biology. Bacteria are very numerous and they release CO2 during respiration. So do plants. Actually, so do we, although it just goes into the atmosphere, to be dissolved in aquaria all over the world.
> 
> A tank of distilled water at 7pH and constant air pressure would have a known quantity of CO2 which would be at it's equilibrium value, it's true. The amount would be dictated by the equilibrium equation. If there was too much CO2, some would leave until it reached equilibrium. If there was too little... well, you know. We know this. Replenishing the CO2 lost through plant photosynthesis must be a combination of atmospheric and in-tank biological factors. It is also my understanding that the biological factors and the atmospheric factor can go from a level below equilibrium to a level above equilibrium overnight.


The biological aspect causes that increase, see how it wasnt by pumping in air?

This supports the notion in my mind. 
I say if these sources are your co2 you need to maximize, a still tank retains more co2 than any boiled high surface agitation system. If you boil the water through air input (not temp boiling obviously) you lose co2


Stay the course !! Not arguing it takes detail to extract this out the cranium. Aquatic Eco.com made me think offgassing always wins thats all, and that Dalton's link didnt extrapolate too well for me in this regard


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## nicuz

Raymond S. said:


> You have not stated what kind of filter you intend to use in this tank.
> The filter may provide enough O2 via circulation. You also have not stated if injected CO2(or DIY CO2) will be used.
> Some filters can be placed on a tank so that they have very good circulation by simply putting it on the end instead of the back of the tank.


I do not inject any CO2. I have an Aquaclear 30 for my 10 gallon tank. Is that going to provide enough circulation or would I need to get a nano/pico pump?


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## Django

This might be good reading in general: http://www.hallman.org/plant/huebert.html

Bump:


nicuz said:


> I do not inject any CO2. I have an Aquaclear 30 for my 10 gallon tank. Is that going to provide enough circulation or would I need to get a nano/pico pump?


I had a 30 in my 10g before I got my current filter, a Fluval U2 internal. You don't need any more circulation - just center where the water comes out on the back of the tank, and keep it turned down to minimum


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## brandon429

the link says water movement keeps co2 at air equilibrium levels, not a net gain. it also doesn't speak of water surface boil, unique to airstones vs pumps. lastly, with the biological contributions mentioned I'm still thinking adding air won't boost. it w drive off that small surplus being made in the tank, driving the total gas only to atmospheric levels and never above.


It's hard to find links that say airstones specifically cause an increase in co2 above atmospheric constant levels. We are very close, I hope it doesn't get silent. The link above didn't address the surface boil loss ratio vs co2 input via airstones. The loss with water pumps is massively lower per aquatic-eco.com site

notion stands but not being ornery! links about offgassing will finalize things. Do read around aquatic-eco site to see what I mean. There is a specific nature of lowering co2 in using airstones mentioned all over that place.


Also consider the tried and true co2 test for reef water; what do we do to a cup of test water for a few minutes before testing ph, to compare that known sample to tank water ph? 

Randy Holmes Farley is rather hard to link against when his own article says to bubble any water sample with air input from a balanced room to offgas co2 totally before comparative ph tests... You can see how this notion became so ingrained!


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## brandon429

This is one counter link

http://www.reefkeeping.com/issues/2004-09/rhf/

see middle portion


More:
http://www.theaquariumwiki.com/Airstone

Non scientific but you see where my info comes from it wasn't just made up to annoy dalton lol


http://www.ratemyfishtank.com/articles/107



What Tom said here was interesting 
http://www.plantedtank.net/forums/showthread.php?t=162480&page=6

I clearly read in the links where airstones bring in co2 used up by plants, I get that clearly.


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## Django

brandon429 said:


> the link says water movement keeps co2 at air equilibrium levels, not a net gain. it also doesn't speak of water surface boil, unique to airstones vs pumps. lastly, with the biological contributions mentioned I'm still thinking adding air won't boost. it w drive off that small surplus being made in the tank, driving the total gas only to atmospheric levels and never above.
> 
> 
> It's hard to find links that say airstones specifically cause an increase in co2 above atmospheric constant levels. We are very close, I hope it doesn't get silent. The link above didn't address the surface boil loss ratio vs co2 input via airstones. The loss with water pumps is massively lower per aquatic-eco.com site
> 
> notion stands but not being ornery! links about offgassing will finalize things. Do read around aquatic-eco site to see what I mean. There is a specific nature of lowering co2 in using airstones mentioned all over that place.
> 
> 
> Also consider the tried and true co2 test for reef water; what do we do to a cup of test water for a few minutes before testing ph, to compare that known sample to tank water ph?
> 
> Randy Holmes Farley is rather hard to link against when his own article says to bubble any water sample with air input from a balanced room to offgas co2 totally before comparative ph tests... You can see how this notion became so ingrained!


I found the Aquatic-Eco technical articles - a lot of information: http://pentairaes.com/customer-service/technical-talks.

I think that maybe an airstone would increase the pressure of air in the water, which would force more air into solution, increasing CO2 and O2 and the rest of dissolved air. The air pressure of the output of an air pump is higher than atmospheric. But it sounds like the prevailing opinion is that it only increases CO2 to atmospheric pressure (or decreases it to equilibrium).

Oh. The dissolved air comes from the water surface driven by the tank's water movement. But if an airstone is being used, the increased pressure in the water would cause gases to be released to a level less than equilibrium. If the airstone is removed, pressure will drop and more CO2 will be able to dissolve, up to equilibrium.

The three things that are involved here are the surface of the water (gas exchange interface), water movement throughout the tank, and the equilibrium level of CO2. We know how a dissolved gas behaves.


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## Okedokey

Look up Flick's laws. Atmospheric concentrations will never provide a flux level significant enough to create a gradient for diffusion that is sufficient; that is an air stone will not increase co2 conc.materially in an aquarium in the time between diurnal phases


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## Django

"Aeration is not good for planted tanks during the day as the increased surface agitation causes CO2 in the water to be released and so plants can suffer from lack of CO2 to grow."

http://www.theaquariumwiki.com/Airstone


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## dpod

I gotta say, I'm enjoying this thread :icon_twis

Diana spelled it out nicely in her post, but as a slightly technical summary:

Air stones create circulation within the tank and drastically increase the surface area. This speeds up the rate of gas exchange between water and atmosphere, but whether the gas is being added or removed from the tank depends on the concentration of dissolved gas and whether it is higher or lower than equilibrium values.

In a tank that is only fish or *only* plants, air stones are useful as there is no biological activity (either respiration or photosynthesis) to balance things out. However, a planted tank with a few fish will probably stay in equilibrium. For most tanks, you only need an air stone to remove dead spots, and a powerhead could give you the same benefits.


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## klibs

In short:

No

You do not need an airstone and the benefit it will provide to your plants is marginal. People usually use airstones to gas out injected CO2 after the photoperiod. IMO a filter with surface agitation / powerheads for flow is a much better way to go.


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## mattinmd

Interesting.

Does anyone have any actual numbers on how much CO2 fish and biofilter end up producing? Graphs of CO2 levels in a non-injected tank over a 24-hour period (obviously stock-level dependent, but useful)?


At this point there's a lot of theorizing, but I'd be more interested in demonstrable measurements.


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## fishbone11

I have read that atmospheric co2 is 200 times higher than dissolved co2 in tank water. What condition would reverse that ratio (day to night?)?
Doesn't seem likely.


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## mattinmd

Air and water are not the same thing. Gasses in air will not equilibrate to the same concentrations in water as they are in air, unless you just replace all the water with air.


You have to account for the very limited solubility of gas in water.

Aeration with air containing approximately 300ppm of CO2 will not create 300ppm's of CO2 in water. It will create about 3ppm, assuming distilled water in a bucket with no other CO2 sources. 

Aeration also won't create water containing 20% oxygen and 78% nitrogen either. You'd have to displace all the water to get to these levels.


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## brandon429

Also, on a near constant basis on this thread we have not discussed off gassing, only input. That is huge for real world applications of using airstones. so far, all content is only about input, not the way you change retention by boiling surface water.

Going away from links how about real world application. my super old high organic bed planted bowl is still, noncirc. co2 comes from air and bed emissions from decay and respiration mentioned above. 

I say adding an airstone reduces co2 in solution but ive no test kit to prove it. I'm claiming leaving the water still holds the internal co2 better than boiling it off while maintaining input from atmospheric sources


if adding an airstone to this specific setup will increase co2 the entire design of the system is 180 reversed. There was no deficit of c02 in this tank, hence no pressure gradients to fill.

Maybe the difference exists in new vs old planted tanks. New tanks non injected have few sources so pumping in may boost co2? But with multiple natural internal sources, bubbling will offgas it faster and bring levels down to what atmospheric inputs would bring


its neat the other pt thread I linked for this. tends to not ever get closure... threads run 50 50 agree disagree

one would think open and shut links exists to close the matter. They need to specifically address surface offgas then ill be happy lol


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## mattinmd

brandon429 said:


> I say adding an airstone reduces co2 in solution but ive no test kit to prove it. I'm claiming leaving the water still holds the internal co2 better than boiling it off while maintaining input from atmospheric sources


I'd say the answer here heavily depends on what the concentration of CO2 is in the water. 

Hence, the crux of the question.. how much CO2 does the tank produce in a day from the fish/biofilter? 

If the production is substantially less than the plants consume, your plants will drive CO2 levels down when the lights are on. At the end of your photoperiod CO2 levels are going to be near zero without aeration. However, aeration won't take them very high, but it will drive them up if they are below equilibrium levels.

If the production is substantially greater than plant demand, your CO2 levels will climb, and aeration will (unhelpfully) reduce them.


We can forward theories either way all day. But does anyone have the numbers to back up one argument vs another? 

It should be obvious that which answer is right is going to vary with stocking ratios, which is probably why there's no good data out there to work with. Injecting CO2 is the much easier and more measurable answer that folks seriously interested end up taking.

You can illustrate extreme examples, and at least as a mental exercise the balances here should work out:

One oto in a 50 gallon tank with heavy planting isn't going to produce squat for CO2, and isn't going to produce enough waste for a large biofilter colony either. Assuming still water, I doubt this tank will have CO2 levels that are above 3ppm at the end of the photoperiod.

One anubias nana plant in a 50 gallon overstocked with fish isn't likely to use much CO2 compared to production by the fish and biofilter.


I've read one source claiming 1 gram of CO2 is produced per gram of dry food added, but that generally makes a lot of assumptions about the energy content of the food. Dried vegetable matter vs dried fish meal have very different energy concentrations. It also assumes a long-term average approach, as fasting your tank doesn't stop your fish from producing CO2, they just consume their energy reserves.

That said, I do think they are roughly on to something, at least in terms of the CO2 production being related to the number of calories used by the system.


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## Okedokey

The answer here is flicks law, going back to principles that were established in the 19th century seems pointless. Too many variables to say equivocally however the draw down and flux levels are too slow to offset gassing off.


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## brandon429

without links we are but opining 

offgassing rates, they have to be considered. its not open and shut like its been said....linx~


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## mattinmd

Okedokey said:


> The answer here is flicks law, going back to principles that were established in the 19th century seems pointless. Too many variables to say equivocally however the draw down and flux levels are too slow to offset gassing off.


Yes, Fick's law is the answer, I don't debate that. 

However, which side we are on is still quite questionable, at least to me.

What are the draw down (plant) and influx rates (fish)? Without those, it is pure speculation that you are gassing off rather than gassing in.


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## Okedokey

No its not. If you read flicks law, it discusses flux. This takes much more time (e.g. over 40hrs) with a diffusion gradient so low. So by that time, we're already in the diurnal stages. Its really quite elemetatry my dear watson.


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## JoeRoun

*We Don't Need None of Those Stinking Laws...*

Hi,

I advocate aeration, one method, air stones are a cheap very efficient way to provide surface agitation and water movement (circulation) it is therefore energy added, disturbing equilibrium.

Simply accept the difference between gasses and liquids otherwise none of the laws help. Fick’s law(s), Henry’s law and so on govern (explain) how things work, as a practical matter people argue about much of this because they would rather think of CO2 and O2, not in solution, but as bubbles. Bubbles are the gas version of precipitates, small if any influence on the solution. 


We can simply say that without oxygen being available the creatures great and incredibly small do not have the ability to produce CO2. 

There is no magic. Air stones provide water movement and encourage gas exchange. 

Providing O2 is the key in this case to encourage the respiration of the critters (including microbes). 



Folks experiencing problems with their canister filters not providing adequate filtration often see marked improvement after adding an air stone or dosing with H2O2. 



The more mature the tank, the less external filtration the higher the CO2 levels, even though the partial pressure hasn’t changed and the system will always try to maintain equilibrium. 



In the proverbial bucket of water left out for say a week (not to be controversial) the density altitude and temperature are the only influences on the amount of O2 and CO2 in the water. Note that if you see bubbles, equilibrium has not been reached.

As an example, tanks using plants and deep sand beds (as substrate) for primary filtration, aeration can easily maintain 5- 7-ppm CO2 with 9-ppm CO2 not being uncommon. To get an accurate measure you may have to measure after photosynthesis has ceased.

In planted tanks even with injected CO2 when photosynthesis is underway the CO2 levels drop (or should drop) drastically, just as O2 levels drop as a result of respiration.

Respectfully,
Joe
FBTB


----------



## mattinmd

Okedokey said:


> No its not. If you read flicks law, it discusses flux. This takes much more time (e.g. over 40hrs) with a diffusion gradient so low. So by that time, we're already in the diurnal stages. Its really quite elemetatry my dear watson.


Actually, I retract my earlier statement.. Fick's isn't the answer.

Fick's laws of diffusion only apply to systems that aren't being forcibly circulated. We are specifically talking about a system where we are forcibly intermixing air and water, as well as circulating the water around a larger pool.

If you've got a goldfish bowl with no pumps, filters, airstones or fish swimming around, then Fick's law's are your answer.


----------



## Okedokey

mattinmd said:


> Actually, I retract my earlier statement.. Fick's isn't the answer.
> 
> Fick's laws of diffusion only apply to systems that aren't being forcibly circulated. We are specifically talking about a system where we are forcibly intermixing air and water, as well as circulating the water around a larger pool.
> 
> If you've got a goldfish bowl with no pumps, filters, airstones or fish swimming around, then Fick's law's are your answer.


Not true at all.

Flicks law(s) are fine for circulated systems, where the diffusion coefficient actually requires movement to be valid (e.g. it is a measurement of movement - K). The only time it becomes inaccurate in this context is where the diffusion coefficient is very low (such as CO2), but even in that case, it works with some help of Graham's law


----------



## mattinmd

Fair, I guess you could think of the air-water boundary as a form of semi-permeable membrane. That's really what you are diffusing across. 

Aeration increases the surface of the membrane, and water circulation ensures the water-side of the membrane doesn't saturate, keeping the diffusion constant from rapidly rising.

Earlier you used 40 hours as a time to diffuse.. Where does that number come from?

Edit: by the way, why do you keep calling them Flick's laws? I'm just making sure we are talking about the same thing... The laws of diffusion are Adolf Fick's, not Flick's. Are we on the same pair of laws, or is there a third I've never heard of, and can find no reference to, under Flick's name somewhere?


----------



## Okedokey

Yeah, typo mate. Its a habit, I have some words I always miss-type!

The ~40 hours comes from various research papers, such as this http://jvarekamp.web.wesleyan.edu/public_htmlA/public_htmlA/CO2/CIW Paper.pdf


----------



## mattinmd

That is a fascinating paper at casual glance, but I'm going to have to look at it in-depth when I have a spare hour or two in order to give it a proper read...

Still, if my first glance is right, the stirred and still freshwater invasion rate changeover (suggesting equilibrium) happens somewhere around 80,000 seconds.. about 22 hours.


----------



## Okedokey

Yeah it will vary, but even the minimum time is too long to justify any idea that surface agitation will increase CO2 in any material manner.


----------



## mattinmd

I don't know that I come to the same conclusion...

Measuring how long it takes water to reach saturation isn't entirely the same as measuring the number of mg of CO2 entering the system when plants are depleting the supply.

The saturation measurement is working against a constantly decreasing gradient....

Aeration against plant consumption would only be working against a decreasing gradient if supplies exceed plant demand.'

Item for further thought:

If the ingress of CO2 into water is so slow, how do drop checkers equilibrate after an hour or so? As CO2 in the tank rises, the drop checker solution CO2 rises too, but with only an hour or so of lag. This means CO2 is leaving the tank water, entering the trapped air in the drop checker, and re-diffusing into the 4dKH solution into the drop checker in a fashion much faster than 40-20 hours.


----------



## JoeRoun

*But Still an Intersting Discussion*

Hi,

So, I will ask again why do we care about Fick's First law?

The air stone or aeration by any means is not the source of the extra CO2, 



it is an energy source
helping maintain the various gases
at established partial pressures, and
the source of any added CO2 is respiration.


I would submit that many of us in the aquarium keeping community significantly underestimate the bio-load of the microbial populations of various persuasions.

And yes that tendency toward equilibrium includes releasing the slightly elevated CO2 levels a bit quicker, but were it not for the circulation and assured supply of oxygen, there would not be increased CO2 to begin with and during periods of photosynthesis, maybe, just maybe our plants benefit.

This is not a difficult concept. 

Frankly, Fick’s law has incredibly little relevance in this discussion. Henry’s law and Le Chatelier's principle (The Equilibrium Law) play a far greater role, but are honestly not all that relevant to the concept or answering the basic question. 



The whole diffusion aspect is a bit of a red herring…

Respectfully,
Joe
FBTB


----------



## mattinmd

Fair, although that does imply that aerating any more than is necessary to provide oxygen to the fish/microbes is counterproductive.

If CO2 isn't ever sourced from the atmosphere (ie: CO2 levels are always high enough that diffusion is outbound or nelgigable), then once there's enough O2 for respiration and well being of fish/biofilter, any extra aeration beyond that point can only serve to drive CO2 downward.

I guess this makes sense at normal and heavy stocking levels, although I do wonder how it plays out in very low livestock situations. Most microbe populations depend on fish waste and/or excess fish food, so will scale down in relation to the livestock population (and feeding).


----------



## JoeRoun

*Kinda Sorta*

Hi, 

Almost.

I guess a couple of other factors, the circulation that keeps agitation that increases oxygen levels also keeps circulation, in particular an upward, almost spherical flow that encourages gas exchange on the one hand but also encourages flow by the plants helping a surplus of CO2 (solvated, not gaseous) to allow the plant to use the CO2 to produce sugar.

The whole thing with the microbes are complex, not just the fish but the plants themselves require a host of critters and fungi to survive, the whole “fixing Nitrogen” is a complex process and without oxygen and the movement of solution through the substrate, the plant suffers and/or dies.

In a mature tank, I think the relationship of microbes and fish population may be more complicated than you imagine. Operating in what might be better described as “waves.” In fact, it is the ignorance regarding the microbial goings on that in my ever-humble-opinion is a major cause of problems people face in older tanks or when they decide to kill things they do not understand. Dose antibiotics randomly or toxins rather than correct the underlying causes, which heaven forfend might take days or weeks to produce desired results.

One other thing to remember (kinda where Henry comes in) is that CO2 and Oxygen in solution operate differently than the CO2 and O2 in our environment. Whereas CO2 and other gases can and do, “displace” one another in the atmosphere; the relationship is different in water. Though, this is probably a discussion for another day.

Respectfully,
Joe
FBTB


----------



## Okedokey

JoeRoun said:


> Hi,
> 
> So, I will ask again why do we care about Fick's First law?
> 
> The air stone or aeration by any means is not the source of the extra CO2,
> 
> 
> 
> it is an energy source
> helping maintain the various gases
> at established partial pressures, and
> the source of any added CO2 is respiration.
> 
> 
> I would submit that many of us in the aquarium keeping community significantly underestimate the bio-load of the microbial populations of various persuasions.
> 
> And yes that tendency toward equilibrium includes releasing the slightly elevated CO2 levels a bit quicker, but were it not for the circulation and assured supply of oxygen, there would not be increased CO2 to begin with and during periods of photosynthesis, maybe, just maybe our plants benefit.
> 
> This is not a difficult concept.
> 
> Frankly, Fick’s law has incredibly little relevance in this discussion. Henry’s law and Le Chatelier's principle (The Equilibrium Law) play a far greater role, but are honestly not all that relevant to the concept or answering the basic question.
> 
> 
> 
> The whole diffusion aspect is a bit of a red herring…
> 
> Respectfully,
> Joe
> FBTB


 Ficks law has everything to do with it because at no point will there be an equilibrium; the best we can hope for is a steady state, even then.....


----------



## JoeRoun

*Okay, All Laws Apply No Matter How Good Your Lawyer*

Hi,

Okay...

Respectfully,
Joe
FBTB


----------



## Okedokey

JoeRoun said:


> Hi,
> 
> Okay...
> 
> Respectfully,
> Joe
> FBTB


Not sure what this means. Either of Fick's laws describes steady state or variable concentrations of gas movements, from gills, to plant cross sections, to soil carbon. These fluxes are completely relevant. The CO2 in the air is relevant too, as this, like any other gas will be impacted by the changes in partial pressures, thus flux. So, im really not sure what you mean. Essentially any biological carbon demand will be across a membrane, thus the flux and partial pressures that other laws describe are meaningless without factoring in Ficks laws... in fact, henry's laws are pointless in this example because it doesn't factor in rate, which is why flux, as per Ficks laws and Grahams' laws mean much much more.

Essentially, yes, an air stone will change the rate, concentration and distribution of gases, but not at flux or rates sufficient to worry about due to the very low dissolution of CO2.


----------



## brandon429

This thread became like the one I linked where tom had posted. everyone cites science laws and its not clear where we stand. Some appear to have changed their stance, not sure.

my notion has not been changed. in any setting where you bubble air from avg co2 room it will introduce atmospheric co2 levels and then be driven off (taking respirational co2 with it) due to offgassing causing a net loss of systemic co2 not a gain, just as I posted first go.

id asked several times for references to include offgassing traits of surface agitation from airstones specifically. .. Not stir bars, not water pumps, and the lack thereof is why my notion stands. 


if you add an airstone to your tank, you are losing co2 and the examples where you wouldn't are far fetched. 99% of the time its a loss. if you want to retain systemically produced co2, or mechanically introduced co2, don't add an airstone. is case closed now or do we have more links that don't address actual airstones ready


----------



## Django

brandon429 said:


> This thread became like the one I linked where tom had posted. everyone cites science laws and its not clear where we stand. Some appear to have changed their stance, not sure.
> 
> my notion has not been changed. in any setting where you bubble air from avg co2 room it will introduce atmospheric co2 levels and then be driven off (taking respirational co2 with it) due to offgassing causing a net loss of systemic co2 not a gain, just as I posted first go.
> 
> id asked several times for references to include offgassing traits of surface agitation from airstones specifically. .. Not stir bars, not water pumps, and the lack thereof is why my notion stands.
> 
> 
> if you add an airstone to your tank, you are losing co2 and the examples where you wouldn't are far fetched. 99% of the time its a loss. if you want to retain systemically produced co2, or mechanically introduced co2, don't add an airstone. is case closed now or do we have more links that don't address actual airstones ready


I agree that there's a net loss of CO2 over 24 hours. Unfortunately, I don't have any hard data to back that up. But if an airstone aerates a fishtank, it must dissolve atmospheric CO2 as well as O2. I think that when photosynthesis is not taking place, CO2 is building up and when it exceeds the equilibrium level it starts to come out of solution through gas exchange at the surface.

As was mentioned in another post, bubbles from an airstone don't have enough surface area to dissolve very much. So it's really through gas exchange at the surface that CO2 transfer is accomplished. That means that the question of whether or not to use an airstone is really a moot point if you have adequate water circulation in the tank.


----------



## dpod

brandon429 said:


> This thread became like the one I linked where tom had posted. everyone cites science laws and its not clear where we stand. Some appear to have changed their stance, not sure.
> 
> my notion has not been changed. in any setting where you bubble air from avg co2 room it will introduce atmospheric co2 levels and then be driven off (taking respirational co2 with it) due to offgassing causing a net loss of systemic co2 not a gain, just as I posted first go.
> 
> id asked several times for references to include offgassing traits of surface agitation from airstones specifically. .. Not stir bars, not water pumps, and the lack thereof is why my notion stands.
> 
> 
> if you add an airstone to your tank, you are losing co2 and the examples where you wouldn't are far fetched. 99% of the time its a loss. if you want to retain systemically produced co2, or mechanically introduced co2, don't add an airstone. is case closed now or do we have more links that don't address actual airstones ready


Sadly, I think you're arguing with no one on this. Adding an air stone helps bring the tank to equilibrium with the atmosphere. If there is accumulated CO2 in the tank, it will be forced out, but it won't go below equilibrium levels. Similarly, if the CO2 levels are below atmospheric equilibrium, more CO2 will diffuse into the water. 

What's more interesting is considering how fast this happens and to what extent this actually affects an aquarium.


----------



## brandon429

it was wierd that the thread got to five pages if no one was disputing that original post. We do that from time to time though heh

I guess it was very important to some to point out that if you bubble an empty carboy that was capped and had no co2 content, that content would increase to atmospheric levels. since we are talking about live tanks, good to know that distinction!


----------



## JoeRoun

*It Just Goes On & On...*



brandon429 said:


> it was wierd that the thread got to five pages if no one was disputing that original post. We do that from time to time though heh
> 
> I guess it was very important to some to point out that if you bubble an empty carboy that was capped and had no co2 content, that content would increase to atmospheric levels. since we are talking about live tanks, good to know that distinction!


 Hi,

Heh, heh, hee… :hihi:


I am sure we could get another 3-pages :icon_eek: out of the “capped” :icon_roll part of your example… :icon_smil


Respectfully,
Joe
FBTB


----------



## brandon429

and that I dont doubt  nice call


----------



## Okedokey

Ok everyone, hold up hold up, Brandon's brain exploded, conversation over....


----------



## brandon429

Capped before the fill, to ensure no incursion before the airstone clearly uncapped after, don't go too hard on me now. Pinning down The variables that make an airstone increase and sustain co2 is like post whack a mole heh


----------



## JoeRoun

*Everyone Can Know What You Meant...*

Hi,

See it doesn’t take much, you don’t even have to wrong,,,:hihi:

Respectfully,
Joe
FBTB


----------



## All4Fish

*humble experience*

wow, amazing read! I am totally new to planted tanks so way out of my element in this discussion. However, in my SR80 planted (48x18x16) , Excel, eco-xotic light after a careful cycling I started adding fish and loosing them. All my parameters were good, no disease, GH climbing a bit, but could not figure out why fish were dying. The SR80 has 2 large pumps and 4 surface outputs so a lot of water movement on top of tank. I finally noticed my pH was much higher at night and lower in the morning so I put an airstone on a timer. 3 days now and no lost fish.


----------



## brandon429

That sounds reasonable, large fish production facilities use air upwelling almost exclusively to remove co2 in large tilapia tanks etc, the power of de stratification and offgassing from simple air is really powerful. Its more significant at losing co2 than with water pumps, if co2 retention was the problem

The part of your post about gh climbing was interesting, are you using different water vs your setup water 

I didn't see where you were injecting co2 so the airstone may not be related to the fish issue although it does seem like that topically. 

To seal in the deal I'd like to know what the actual pH readings are pre airstone at 7 am and post airstone at 7 am


----------



## All4Fish

Hi Brandon 429! To answer:
I am using the same water as start up approx 6 weeks ago and not injecting CO2, just using Excel. I will check pH tomorrow early am (it's all ready noon here!), but it has been high 8.4 in early evening versus 7.4 in the am, pre-airstone. KH has dropped slightly from 4 to 5 to 3 to 4. Does this make sense?!


----------



## brandon429

im surprised you have that much of a co2 issue, can you post a full tank shot lemme see substrate


----------



## All4Fish

Hi, here is a photo (if I did it right!); sand in foreground and eco-complete in background about 1.5" deep I think. pH this morning was 7.4; seems to rise to 8.4 by early evening.


----------



## ForensicFish

After reading 5 pages of "stuff" I have come to a conclusion. Ready for it?

No, you do not an airstone, but can use one if you like. A small HOB will probably accomplish the same with more efficiency regardless of any gas law that doesn't really change anything on how someone operates their planted fish tank.


----------



## brandon429

All4

Thats very nice 

If an airstone is bringing equilibrium to the morning phase then it strongly implies co2 what a challenge to locate the source. Not tons of decay. A new bright clean highly aerobic tank 

High surface area top
Not overstocked w fish
No co2 injection but airstone bubbling drives up pH 
Nothing brings an excessive bacterial load to that tank look how clean it is no huge detritus deposits or sludge anywhere 

I did read correctly you aren't injecting co2 right

Acidification by soil was first guess but that's not something to offgas with the airstone 

Randy Holmes Farley in his article about co2 and alkalinity in the reef tank mentions co2 retentive homes 

Is yours gas heated

At some point it would be neat to test on non API kit and compare differences during the high acidic phase of the mornings 

On many reef threads during problem tank fixes we have the poster inputting three different readings per param when using three varying test kits 

There online articles comparing the discrepancies as well 

Rule number one in tank troubleshooting is don't take any one kit one off reading, assume all unnamed test params are API, never take the initial reading as the whole truth. Suspect and verify


----------



## All4Fish

Thanks for your comments, things to think about. You are right, there is no accumulation of sludge, pretty clean, I do about 8-10% water change per week. I keep top of tank half open at night so CO2 can escape. Also, add Excel in am, not night. I am going to try using RO mix for water changes to lower GH and pH and add a powerhead to move water at bottom of tank (as this is an overflow filter styled tank ) and will see what that does. 
Yes, gas heated house. Will try another test kit, could be interesting. Just tested oxygen and it is 8ppm at night and dropped to about 6ppm in morning so I still suspect an oxygen issue.


----------



## Okedokey

ForensicFish said:


> After reading 5 pages of "stuff" I have come to a conclusion. Ready for it?
> 
> No, you do not an airstone, but can use one if you like. A small HOB will probably accomplish the same with more efficiency regardless of any gas law that doesn't really change anything on how someone operates their planted fish tank.


Citation?


----------



## ForensicFish

Okedokey said:


> Citation?


Citation for what?


----------



## JoeRoun

*Cannot Violate the Laws of Chemistry or Physics*



ForensicFish said:


> Citation for what?


 Hi

“…accomplish the same with more efficiency regardless of any gas law that doesn't really change anything…” I Imagine.

Respectfully,
Joe
FBTB


----------



## Okedokey

JoeRoun said:


> Hi
> 
> “…accomplish the same with more efficiency regardless of any gas law that doesn't really change anything…” I Imagine.
> 
> Respectfully,
> Joe
> FBTB


yeah


----------



## ForensicFish

A small HOB will move more water than an air stone. It can also provide water oxygenation in the matter of a splash.

So again I ask a citation for what? You will get more overall function from An HOB than just an air stone.

Spare me the research jargon that doesn't apply to anything other than trying to prove a point on an online forum.


----------



## brandon429

your claims are not holding water. But the context was important
we weren't battling for oxygenation in this thread it was co2 so your statement needs to relate to co2 to be relevant

an airstone of usual size will offgas co2 better than a usual sized hob was the point you missed

the specific physical reasoning is bottom level laminar tank turnover and exposure to top surface vs hob which affects only the top layer

I think in your challenge here you aren't working from that angle, just that a hob works better in general. which is why that's irrelevant for this thread, unless you got linx


----------



## ForensicFish

Sigh.....



brandon429 said:


> your claims are not holding water. But the context was important
> we weren't battling for oxygenation in this thread it was co2 so your statement needs to relate to co2 to be relevant
> 
> an airstone of usual size will offgas co2 better than a usual sized hob was the point you missed
> 
> the specific physical reasoning is bottom level laminar tank turnover and exposure to top surface vs hob which affects only the top layer
> 
> I think in your challenge here you aren't working from that angle, just that a hob works better in general. which is why that's irrelevant for this thread, unless you got linx


Let me remind you what the initial question of this topic was:

"I plan on keeping a few beginner plants (cryptocorynes, java fern, java moss, anubias) with no CO2.

Is an air stone going to be beneficial to my plants/fish or not?"

Did you read that correctly? That question has nothing to do with the 8 pages of scientific jargon that relates to air stone off gassing, co2 levels and blah blah blah. The simple answer to the original question is yes. It can be beneficial.

This is the problem I see all the time on this forum. Some one asks a simple question and it turns into an 8 page "discussion" on something that has nothing to do with the question in the first place.

You said my statement needs to be about CO2 to be relevant. Really? The initial question was not even about anything CO2 related! All it states is that the member (who posted the question) is not using CO2. That is it! Nothing else. And you and others went off on this air stone/CO2 tangent that has nothing to do with the original question.

I am all for technical discussions as people can benefit from this. However, I am going to go out on limb and say the member who posted the initial question is new the planted tank hobby. So do you think your 8 pages of scientific discussion is going to truly help that member? Probably not. All you have to do is provide the most effective answer in the most simple of terms. And in this case, it would be "yes, an air stone can be beneficial". Nothing more or nothing less. Technical discussions need to be posted as such and not as a result of members trying to over complicate things for new members.

I hope this member wasn't put off by this discussion and continues with their hobby in the world of planted tanks.


----------



## jrill

ForensicFish said:


> Sigh.....
> 
> 
> 
> Let me remind you what the initial question of this topic was:
> 
> "I plan on keeping a few beginner plants (cryptocorynes, java fern, java moss, anubias) with no CO2.
> 
> Is an air stone going to be beneficial to my plants/fish or not?"
> 
> Did you read that correctly? That question has nothing to do with the 8 pages of scientific jargon that relates to air stone off gassing, co2 levels and blah blah blah. The simple answer to the original question is yes. It can be beneficial.
> 
> This is the problem I see all the time on this forum. Some one asks a simple question and it turns into an 8 page "discussion" on something that has nothing to do with the question in the first place.
> 
> You said my statement needs to be about CO2 to be relevant. Really? The initial question was not even about anything CO2 related! All it states is that the member (who posted the question) is not using CO2. That is it! Nothing else. And you and others went off on this air stone/CO2 tangent that has nothing to do with the original question.
> 
> I am all for technical discussions as people can benefit from this. However, I am going to go out on limb and say the member who posted the initial question is new the planted tank hobby. So do you think your 8 pages of scientific discussion is going to truly help that member? Probably not. All you have to do is provide the most effective answer in the most simple of terms. And in this case, it would be "yes, an air stone can be beneficial". Nothing more or nothing less. Technical discussions need to be posted as such and not as a result of members trying to over complicate things for new members.
> 
> I hope this member wasn't put off by this discussion and continues with their hobby in the world of planted tanks.


You have said something about responses to questions I have wanted to say many times.


----------



## brandon429

ok forensic then we can just disagree. The original answer to him was its better not to use an airstone for the reasons listed , you say it doesn't matter and thats where it stands. nbd.


----------



## ForensicFish

brandon429 said:


> ok forensic then we can just disagree. The original answer to him was its better not to use an airstone for the reasons listed , you say it doesn't matter and thats where it stands. nbd.


 
And what reasons are those?


----------



## ForensicFish

mattinmd said:


> Needed, no. Beneficial, maybe.
> 
> Either surface agitation or airstones will aerate the water. If you have a lot of surface agitation, you are probably already well aerated and airstones will probably only help move water around.
> 
> I personally like to use them to avoid dead spots in corners behind ornamnets, etc. The extra aeration is probably more than I need, but it doesn't hurt. That said, I'm a bit old-school and airstones are certainly not in-style anymore. Circulation pumps are more the current style, as you can aim them anywhere.


 
This was a perfectly good answer two posts down from the original question. The "issues" were created by you and other members.


----------



## brandon429

if you dont like long mundane posts dont read them, but if you are advising he doesnt need any extra co2 to help start the tank then simply type it. the way you write with no real substance is the greater annoyance.

your last several posts were asked to be backed up and we see that you haven't so that means you are here to opine and so was i, nbd.


----------



## ForensicFish

You just don't get it.

Anyway, I bet if you ask the members on this forum who have a ten gallon tank that employs a HOB filter or a sponge filter powered by an air pump that the majority have no issues with a O2/CO2 balance or off gassing or whatever.

Why there may technical research data that shows a relationship between an air stone, CO2 and off gassing etc. I would probably say that the majority of the members with tanks, including myself have not had issues with any CO2/O2 off gassing or whatever unless they are injecting CO2.

While your technical data may show gassing issues when using an air stone, I don't believe that it really matters when it comes down to running a planted tank. Unless you can find me someone who has/had significant gassing issues that resulted from using an air stone in their planted tank, I will currently view all your technical points as irrelevant.


----------



## brandon429

no I wouldnt debate that it couldnt be done with or without an airstone, plants would grow for me either way its just fun to make offers around the soundest science and I thought he'd be better off w a little extra co2. for that, seems we made a good case 


what we typed isnt useless either, for example you wrote:

*I would probably say that the majority of the members with tanks, including myself have not had issues with any CO2/O2 off gassing or whatever unless they are injecting CO2.*

but just last page all4 fish is posting a dynamic where what you discount does matter. Just last page... offgassing to help w pH issues and we are actually looking for the source of the co2 which is ironic here. 


seems you were trying to distract from that, how about contribute.


where do you think all4fish is getting the ph swings from that are mitigated by just an airstone? if it was alk issues Id not expect offgassning to be such a stark control for an entire point of pH drop.


----------



## brandon429

crickets


----------



## Xiaozhuang

brandon429 said:


> crickets


We eat those here. Okay just joking. 

I think both of you have worth while points.

I think that ForensicFish is focused on giving the OP a general answer; which is that most low tech tanks function fine with or without an air-stone. Drawing from the general conclusion that if it makes such a significant difference it would have been standard by now to have one or not. The fact that we have to actually measure pH etc, rather than just looking at tanks to see the difference probably means that the impact if any is small. Answering the OP's question within their scope is important. (the guy is growing anubias for god's sake)

Brandon on the other hand, wants to search for an optimized solution for the rest of us who use low tech tanks. This topic has not been that well explored it seems, and having a CO2 edge in low tech tanks can be impactful (though in older posts Tom Barr himself claims that it makes no significant difference). However, perhaps it may be more polite to start another thread, rather than transmute the OP's simple question into one that is much more technical in nature. 

My recommendation to Brandon is that if you want to test for CO2 retention/degassing, you cannot rely on other hobbyists casual measurements because most casual hobbyists tanks fluctuate far too much and they may lack the technical equipment for accurate measurements. pH can flux for other reasons than CO2 etc. Different substrate types with different microbial activity may yield different results, plant mass grow and water changes are made... too many variables. The empirical method is to setup two tanks or more, similar substrate and time horizon etc with the only difference being use of airstones. Use the typical scientific method and record the differences across a period of time. Since you're looking for small changes (I mean you aren't expecting a 30ppm CO2 increase right?) , measurement accuracy comes into play. And of course, the ultimate proof is having tanks, setup similarly except for airstones, where the one with airstone turns out different from the one without. And once the outcome can be replicated, then you know the theory works. I think theory craft has brought us as far as we can go in this scenario; at the end of day people need to see application. If you're committed to the idea, empirical testing is the next step.

To throw an additional spanner into the mix.... I have a theory that using dirt rather than substrates like eco-complete/flourite + osmocote allows better growth in low tech tanks; because the increased microbial activity is beneficial for plants or that said activity produces CO2, or soil composition provides carbon. The combination of one or more of the effects (I have no idea why actually, and have no means to test) allows harder plants to grow in low tech settings more easily. While I'm not sure why, I've done enough empirical testing to produce reasonably good results. Growing DHG, Glosso, AR minis in low examples can be found in this thread;

http://www.plantedtank.net/forums/showthread.php?t=750105&highlight=dhg+co2

The factors that I think work so far are; large soil to water volume ratio, shallow tanks, good/strong lighting, dirt substrate, good flow. I have a nagging suspicion people don't actually believe those are low tech tanks


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## brandon429

Well said 

Whats your take on allforfishs tank issue from previous page


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## Xiaozhuang

Hmm...

I can divide data into 2 broad categories:

Tightly controlled scientific data; where variables are reduced and I can narrow down cause and effect to a few variables. There is usually a control system for comparison. With this method, one can draw solid conclusions from a small data set.

Anecdotal data from casual aquarists; where tanks/livestock flux for a wide variety of reasons and narrowing down causation is difficult. If using such data, a much wider sample set is necessary to draw usable conclusions. i.e. 10 people notice visually better growth in plants after removing the air-stone, but observe lousier growth when adding it back. 

I'm recommending the former, because most aquarists tank flux quite a bit.

In allforfishs case, with uncalibrated test kits, and him trying out new stuff daily, with fluctuating KH etc, there really isn't any usable data. Even if we strongly suspect something, until it is replicable in other people's tanks in a significant way, we'll just be boxing shadows. 

Working on controlled experiments is a far better method. Working on anecdotal experience from aquarists can lead to all sorts of false correlations. This is most seen in the nutrient dosing diagnostics portion of this site. "When the only tool you have is a hammer, you treat everything like a nail" - when people can only test for nutrient levels, but cannot test for CO2/light/bacterial activity/O2/flow/other variables, everyone draws the conclusion that when their plants don't grow well its a nutrient deficiency.


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## ForensicFish

Xiaozhuang said:


> Hmm...
> 
> I can divide data into 2 broad categories:
> 
> Tightly controlled scientific data; where variables are reduced and I can narrow down cause and effect to a few variables. There is usually a control system for comparison. With this method, one can draw solid conclusions from a small data set.
> 
> Anecdotal data from casual aquarists; where tanks/livestock flux for a wide variety of reasons and narrowing down causation is difficult. If using such data, a much wider sample set is necessary to draw usable conclusions. i.e. 10 people notice visually better growth in plants after removing the air-stone, but observe lousier growth when adding it back.
> 
> I'm recommending the former, because most aquarists tank flux quite a bit.
> 
> In allforfishs case, with uncalibrated test kits, and him trying out new stuff daily, with fluctuating KH etc, there really isn't any usable data. Even if we strongly suspect something, until it is replicable in other people's tanks in a significant way, we'll just be boxing shadows.
> 
> Working on controlled experiments is a far better method. Working on anecdotal experience from aquarists can lead to all sorts of false correlations. This is most seen in the nutrient dosing diagnostics portion of this site. "When the only tool you have is a hammer, you treat everything like a nail" - when people can only test for nutrient levels, but cannot test for CO2/light/bacterial activity/O2/flow/other variables, everyone draws the conclusion that when their plants don't grow well its a nutrient deficiency.


Every single members' planted tanks are different from one another on a large variety of levels. I never understand why anyone tries to say, "you need to do this or this to achieve this. What works in someone else's tank, could not work in anothers. As Xaio stated, E.I. dosing topics are notorious for saying you have this, you need to dose this. No. Because every single planted tank is different, all we can provide are templates or guidelines for people to EXPERIMENT with. 

That is why I cannot stand these "technical" discussions where people cite stuff just to make themselves come off as intelligent. Regardless of what any scientific paper tells me, I will have to experiment with different things based on how my planted tank is setup and how it currently operates. The only stuff that works or doesn't is based on my own observations from my tank. Yes, I learn tips and things, but in the end it is how it all works for you, no one else. 

So Brandon, I never said the data you cited was wrong. I simply said it was irrelevant. And the reason I say that is because unless the member who posted the original question, experiments with the whole air stone thing, or anyone else for that matter the technical data is worthless because it does not apply to anything. If someone says, yea I need to try the air stone thing because of gassing issues, your posts and data would be spot on. Not so much here.

We have to start answering the most basic questions that people ask with the most simple answers. We forget that what works for us, may not work for any other person. For example, people who grow hair grass in low light. Never ever worked for me no matter how much I try to "copy" their setup. We have to stop treating members tanks as our own and help them experiment themselves.


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## Okedokey

ForesnsicFish, your posts are really arrogant. You claim to keep it general yet make completely specific responses with no background or support. The OP's question was would an airstone be beneficial. The answer is yes as it improves oxygenation, particularly at night. That has been answered.

You have no right to moderate what we talk about.

There is significant differences, pros and cons regarding the techniques (e.g. airstones). It is still based on physics and science so your comment that it doesn't matter is ill-founded. http://www.fao.org/docrep/x5744e/x5744e0m.htm#2. aeration devices for fish ponds

Some of us like to discuss this in more detail.


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## ForensicFish

Okedokey said:


> ForesnsicFish, your posts are really arrogant. You claim to keep it general yet make completely specific responses with no background or support. The OP's question was would an airstone be beneficial. The answer is yes as it improves oxygenation, particularly at night. That has been answered.
> 
> You have no right to moderate what we talk about.
> 
> There is significant differences, pros and cons regarding the techniques (e.g. airstones). It is still based on physics and science so your comment that it doesn't matter is ill-founded. http://www.fao.org/docrep/x5744e/x5744e0m.htm#2. aeration devices for fish ponds
> 
> Some of us like to discuss this in more detail.


Arrogant? I haven't stated anything of sort. I'm sure the research you found is sound. However, show me a real-world application in regards to planted tanks. Like I stated earlier, I am not against technical discussions. But I believe there is a place for those types of discussions. I find it entertaining when people get into technical discussions about things that are not really applicable. For example, you have all this data based on laboratory studies. Great. I would like to read one based on a persons planted fish tank.

The whole point I was trying to make is there is a place and time for technical discussions. I wish experienced members would simply answer the questions that are asked and not complicate matters when it is not truly needed. Talk about whatever you want, I don't honestly care.


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## Okedokey

The arrogance comes from thinking your approach is the right one, and everyone else here is not allowed to discuss what they want. The link i posted above is real-world, with an extensive bibliography. This is a forum for discussion, and much of planted tank/aquarium is based on technical. Anecdotal input is rarely any more valuable. If you aren't enjoying the discussion, its probably best to unsubscribe.

Lets not argue any further. More here http://www.barrreport.com/showthrea...than-others-and-why-some-folks-gas-their-fish


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## ForensicFish

Okedokey said:


> The arrogance comes from thinking your approach is the right one, and everyone else here is not allowed to discuss what they want. The link i posted above is real-world, with an extensive bibliography. This is a forum for discussion, and much of planted tank/aquarium is based on technical. Anecdotal input is rarely any more valuable. If you aren't enjoying the discussion, its probably best to unsubscribe.
> 
> Lets not argue any further. More here http://www.barrreport.com/showthrea...than-others-and-why-some-folks-gas-their-fish


 
I just read your "pond" citation. It basically states that fish ponds can become oxygen deprived through various mechanisms and using an air stone will help oxygenate the water. For one its a pond, not a planted tank. Two, it doesn't provide anything related to the pros and cons of using an air stone.

The barr report citation states that oxygenation will help diffuse co2 out of the tank because of a possible scum layer. Cool. Doesn't say anything bad about using an air stone.

Good. Great. Grand. Both of these articles still don't really apply to the initial question of this thread which is, " I have these plants. Is an air stone necessary?" I will ask again to be shown data or tanks that have issues when an air stone was used. 

An air stone is used for oxygenation and water movement. In the barr citation, aeration is used to combat a scum layer which helps reduce co2 levels in the water column. 

So basically, use an air stone to help oxygenate your tank if you are having issues with oxygen levels. Its not that complicated. All this technical data and citations are irrelevant because they do not provide us with anything we don't already know. Do you think a person new to the planted tank scene can use any of that info? 

Air stones oxygenates a planted tank. Simple and done. Why do we want to get so technical about that?


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## brandon429

Forensic
we do answer it without all the type, then someone uber cool flat challenges it w no substance....  then the pages ensue

we needed your type of challenge spirit to get this bad boy out to 6 pages. 

This discussion went from philosophical to practical right when all4 presented his issues and crickets went to chirping only briefly interrupted by more philosophy and no specifics. at least we got it pinned down to a gassy house or a test kit verification needed. i mean how often do you get your home heating system predicted in a forum

what you seem to do is just hack on us who actually attempt but without linking anything.
I know you dont like the technical banter, but we dont like baseless distraction.


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## brandon429

one guy reads our mess of typing and relates it to a prob his tank was experiencing and reverses the prob

another guy reads it and gets all mad. outcome originated in the source.


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## ForensicFish

Brandon, I have no idea what you just said. 

But anyway, have a good upcoming holiday.


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## brandon429

ok u too


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## Okedokey

ForensicFish said:


> ...Good. Great. Grand. Both of these articles still don't really apply to the initial question of this thread which is, " I have these plants. Is an air stone necessary?" I will ask again to be shown data or tanks that have issues when an air stone was used.


No one said that there were issues. The original quesiton was " Is an air stone going to be beneficial to my plants/fish or not? " To determine if it will be beneficial, one needs to know the net effect.

Various users were enjoying the discussion (OP never returned) and then you have the arrogance to come back with:



ForensicFish said:


> After reading 5 pages of "stuff" I have come to a conclusion. Ready for it?
> 
> No, you do not an airstone, but can use one if you like. A small *HOB will probably accomplish the same with more efficiency regardless of any gas law that doesn't really change anything on how someone operates their planted fish tank.*


I asked for a citation. You didn't give me one.

The fact is, an airstone is around 15% - 20% (dependant on study) more efficient than sprays and HOB surface agitation methods (_Scott, K.R, Comparison of the Efficiency of Various Aeration Devices for Oxygenation of Water in Aquaria, 2011,Journal of the Fisheries Research Board of Canada, 1972, Vol. 29, No. 11 : pp. 1641-1643_ )

So please, if you're going to call what we discuss 'stuff' and make statements like it doesn't matter, please either unsubscribe or get it right.

We are, afterall, allowed to discuss things here.
*
*


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## ForensicFish

Okedokey said:


> No one said that there were issues. The original quesiton was " Is an air stone going to be beneficial to my plants/fish or not? " To determine if it will be beneficial, one needs to know the net effect.
> 
> Various users were enjoying the discussion (OP never returned) and then you have the arrogance to come back with:
> 
> 
> 
> I asked for a citation. You didn't give me one.
> 
> The fact is, an airstone is around 15% - 20% (dependant on study) more efficient than sprays and HOB surface agitation methods (_Scott, K.R, Comparison of the Efficiency of Various Aeration Devices for Oxygenation of Water in Aquaria, 2011,Journal of the Fisheries Research Board of Canada, 1972, Vol. 29, No. 11 : pp. 1641-1643_ )
> 
> So please, if you're going to call what we discuss 'stuff' and make statements like it doesn't matter, please either unsubscribe or get it right.
> 
> We are, afterall, allowed to discuss things here.
> *
> *


Ok, so an air stone is more efficient for surface agitation than a spray bar or HOB. Doesn't change anything in regards to all the gas law research that was cited. If you feel that if someone is using an air stone in their planted tank, that they need to be well aware of all the gas laws that effect off gassing, co2 etc. then go for it.


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## ForensicFish

Out of all of this, my only question would be; is all this technical data/discussion necessary given what the original question was? I mean the person simply asked " I have these plants and no co2. Is an air stone needed/beneficial.

It is a very simple question with a very simple answer. Like I said earlier, I am not against technical discussions, but not at the expense of a members initial question. Take a look at another discussion in the low tech thread. A person asked a simple question about LED light fixtures. The member Django, went about posting technical data that doesn't even answer the persons question. Keep in mind, Django is the same member who started the technical discussion on here in regards to gas law. And again, those technical posts do nothing to really answer the initial question.

I could care less about the technical data or the discussion. I just wish people would answer each others questions as simply and effectively as possible without all the unnecessary complications of technical data. And in this case, there was no need for all the technical stuff.


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