# CO2 Tube Diffuser (New Design?)



## Deanna (Feb 15, 2017)

Following the recent ‘re-discovery’ that diffused CO2 bubbles might benefit plants more than using a reactor (thanks to @Xiaozhuang pointing us to the T Barr study), I decided to try it. It does seem that I can drive CO2 higher (.4 increase in the Ph drop, Kh ~1dKH, pH7.2 drop to 5.4) without affecting the fish. I’m currently awaiting any change in plant performance, but have noticed a drop-off in GSA activity, probably indicative of increased plant performance. However, the purpose of this post is to share a new (to me, anyway) way to diffuse CO2.

Essentially, this is a design for laying tubing on your substrate that acts as a very long CO2 diffuser. I found that creating needle-sized holes in the urethane CO2 tubing I use allows tremendous design flexibility, while delivering minute, ceramic diffuser-sized bubbles throughout the entire tank, from the bottom of the tank. Placing the tubing under the plants allows the bubbles to get hung up in the plants. Very few make it to the surface so, absorption can occur as the bubbles stick to the leaves, which is considered ideal …and there is no swirling haze of bubbles, such as I used to get with an in-line atomizer, to affect the pristine clarity of the water. 

My initial design (pictured) which covered about half the tank floor, under the plants, has been replaced with a single line that traverses the back of the tank. I have about 12” of diffusing activity on each end of the three-foot tubing (where the bulk of my stems plants are), with a non-diffuser section in the middle. The pinholes are spread along these two 12” sections at each end and there are about 3-6 holes in any given inch of these tubing sections. 

The holes can be bunched in small sections of the tube for different effects and, being a tube, you can serpentine it anywhere along your floor. An additional benefit seems to be that water can not enter these pinholes when the CO2 is off. This means that check valves may not be necessary or, at least, no more worry about their failure.

To make the minute holes, I use pliers to push a small needle through the sides of the tubing. I use urethane tubing (Clippard .250” OD) and I think CO2-type tubing is necessary given the much greater wall thickness of this type of tubing. Thinner tubing, such as silicone tubing, would likely allow much larger bubbles through the holes. 

You will need the pressure from a pressurized system to push the CO2 through these holes. The pressure needed is a function of the number of holes and the bubble size. If pressure is too high, the bubbles are large enough to immediately rise to the surface where they do not get absorbed well. For example; right now I have a three-foot length of tubing laid along the back of the tank substrate. Many holes are in the first foot and the last foot (nothing in the center). Given the number of holes I have, I am sustaining about 35 ppm of CO2 with 15 psi in a 29-gal tank.

To plug the end of the tube, I use a plug for drip irrigation (Rainbird – 30 of them for $7 on Amazon), but you might be able to melt the tube end closed. I also use drip irrigation parts for the various “T”, right-angle and other connectors, as well as the long black tube that runs along the inside corner of the tank top to the substrate where it connects to the main urethane tubing (pictured). The CO2 and drip irrigation tubing comes coiled. To straighten it out, I straightened a wire hanger, inserted it into the tubing and placed it in an oven for 10 minutes at 150F.

The process I use to optimize the bubble size and CO2 ppm is this:

I start with the tubing configuration mentioned above (your design may be different based upon plant layout, tank size, etc.) and about 20-25 psi. I lay this in the front of the tank to observe the bubbles. Usually, it starts by having large bubbles that immediately rise to the surface and are wasted. However, it can take a few hours for the bubble sizing to settle in, so wait at least three hours to see if any changes are needed. The bubbles, ultimately, should be so small that they rise very slowly and are difficult to see from several feet away, much like a ceramic diffuser would create. If you still have large bubbles after three hours, put more holes in the tube. Repeat this process until you have no large bubbles for a day. Then place the tubing where you want it. Now, you can adjust the pressure as you need to reach your CO2 ppm target.


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## MCFC (Feb 12, 2017)

pictured?


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## Deanna (Feb 15, 2017)

Delete - not relevant to topice?


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## MCFC (Feb 12, 2017)

There is a distinct lack of picture haha


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## Deanna (Feb 15, 2017)

Delete - not relevant to topic


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## MCFC (Feb 12, 2017)

I don't see a pic or even a broken link or anything. Just looks like a normal post. If you hadn't said "pictured" I wouldn't have had a clue. Weird...

Sounds like an interesting idea though. I was recently thinking about DIYing a PVC return that sits along the substrate. Maybe I'll combine the two and add some tubing just below the holes in the PVC..


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## Deanna (Feb 15, 2017)

Delete - not relevant to topic


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## burr740 (Feb 19, 2014)

No pic, and Im not seeing a link or bbcode in the quote.

As for the idea it sounds interesting (too bad we cant see it!) You can also cram a piece of regular cotton ball in the end of the line to make fine bubbles, or a bamboo chopstick


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## Deanna (Feb 15, 2017)

burr740 said:


> No pic, and Im not seeing a link or bbcode in the quote.
> 
> As for the idea it sounds interesting (too bad we cant see it!) You can also cram a piece of regular cotton ball in the end of the line to make fine bubbles, or a bamboo chopstick


Can't figure it out: I can see the picture in the post, but no one else can. It's via a BB code. Can't even post the url as a link. No response from tech support. I'm wondering if they are having site problems. Here is the BB code ...if it's any help:
https://www.plantedtank.net/forums/picture.php?albumid=23330&pictureid=107527
Can also send you a picture.

Unlike an in-line atomizer (creates hazy tank), ceramic diffuser (single-point heavy stream of minute bubbles) or a cotton ball, this provides the opportunity to have streams of CO2 (ceramic diffuser-sized bubbles) come up from the substrate level anywhere in your tank at points of your choosing (mine are coming up through the interior of the stem plants). So, because they can be spread out across the entire tank, the streams are very small, making them difficult to see. However, the combined effect is a lot of CO2 being put in (I'm now pushing a 2 point pH drop and fish are fine). If you like the look of bubbles coming up here and there in a heavier stream, you can group the holes anywhere along any length of tubing you want to use - great design flexibility.


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## natemcnutty (May 26, 2016)

I'm basically picturing a soaker hose type concept except opposite of how it would be used in a garden.

My concern would be around clogging in the long term. If any of them stop putting out CO2, would it be very apparent? How do you clean that out when it does?


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## sdwindansea (Oct 28, 2016)

Even clicking on your link does not show a picture for me. I like the concept a lot, especially since it eliminates a lot of the plumbing difficulties and potential hazards (e.g. leaking inline atomizer). What PSI are you running from your regulator? I'm guessing this would also be dependent upon the length of tubing and number of holes.


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## Deanna (Feb 15, 2017)

natemcnutty said:


> I'm basically picturing a soaker hose type concept except opposite of how it would be used in a garden.
> 
> My concern would be around clogging in the long term. If any of them stop putting out CO2, would it be very apparent? How do you clean that out when it does?


Similar concept to a soaker hose, although I first visualized it when thinking about my drip irrigation system. Shouldn't be any clogging. What would clog it? There is no back-flow through the system. Any conceivable clogging would also apply to the clogging of any CO2 tubing into a diffuser or reactor, of which I have never heard about.




sdwindansea said:


> Even clicking on your link does not show a picture for me. I like the concept a lot, especially since it eliminates a lot of the plumbing difficulties and potential hazards (e.g. leaking inline atomizer). What PSI are you running from your regulator? I'm guessing this would also be dependent upon the length of tubing and number of holes.


Yeah, I can't get any response from TPT on the picture posting problem. 

Current PSI is about 30, only because that's what I've been running all along. When you speak about length and number of holes, you are probably thinking about the length of the tube _beginning from the first hole _ (my tubing, up to that point, is about 40 feet from the regulator). There will be varying levels of bubbles along the path, but my observations are that each hole is producing some amount, perhaps a little more near the end.

If either of you want pictures, I can pm them to you.


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## Letsfish (Jul 11, 2017)

Deanna could you send me a picture.


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## Deanna (Feb 15, 2017)

Letsfish said:


> Deanna could you send me a picture.


Sent. Let us know if the link is view-able.


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## Letsfish (Jul 11, 2017)

Deanna the link did not work.


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## Deanna (Feb 15, 2017)

Delete - not relevant to topic


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## Deanna (Feb 15, 2017)

@MCFC, @burr740, @natemcnutty, @sdwindansea, @Letsfish:

Found a way to get the image to work. Picture is in the OP.


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## sdwindansea (Oct 28, 2016)

Thanks for getting the picture posted. It is a really interesting idea and I love the creativity. Like someone else mentioned earlier, the maintenance (keeping the pin-holes from clogging) could be problematic.


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## Deanna (Feb 15, 2017)

sdwindansea said:


> Thanks for getting the picture posted. It is a really interesting idea and I love the creativity. Like someone else mentioned earlier, the maintenance (keeping the pin-holes from clogging) could be problematic.


Yes; I noted the clogging concern, but can't see what would possibly clog it. These are holes created by forcing a needle through the tubing. So, they aren't holes so much as they are rips. When the CO2 is on, the rips are forced open with escaping CO2. This means that, once CO2 pressure is turned off, the rips close tightly again. I can't even see any water that backflows in the tube when CO2 is off, in the way that I could see it with ceramic diffusers.


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## SingAlongWithTsing (Jun 11, 2015)

idk why but it kinda reminded me about filipe's tanks with the bottom return

https://youtu.be/MsBlR5a7v8U?t=1m29s


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## Deanna (Feb 15, 2017)

SingAlongWithTsing said:


> idk why but it kinda reminded me about filipe's tanks with the bottom return
> 
> https://youtu.be/MsBlR5a7v8U?t=1m29s


I don't quite see the resemblance to that. It reminds me more of a soaker hose, as @natemcnutty mentioned, or my original idea source, which is a drip irrigation system.


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## Letsfish (Jul 11, 2017)

I have one of them small drip systems that I use for hanging baskets and potted plants on my deck. I know I have a bunch of them 1/4" T, right angle and straight connectors for them out in my garden shed, now all I have to do is go out there and find them.:wink2:


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## Edward (Apr 11, 2005)

How do you prevent the tubing from floating and how is it different than using two diffusers, in terms of filling the aquarium with CO2 bubbles?


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## Deanna (Feb 15, 2017)

Edward said:


> How do you prevent the tubing from floating and how is it different than using two diffusers, in terms of filling the aquarium with CO2 bubbles?


Sorry @Edward ...just saw your post because I was referencing the thread elsewhere.

I've since modified the pictured design to one simple straight tube across the back. To answer your questions:

- The vertical black irrigation tube that connects from top to bottom is somewhat rigid and holds that side of the tube in place. The rest of the diffuser tubing doesn't seem to want to rise, although some ends were sticking up (not from buoyancy) so I wrapped some plant anchors around the ends of those and that held them down.

- Focused diffusers, such as ceramic, create a very visible stream. I wanted as low a visible footprint as possible. My Atomic in-line created hazy water, this doesn't. I do hold about 35-40 ppm CO2. So, it is obviously filling the tank. Most of the minute bubbles get hung up in the plant mass, so they dissolve before reaching the surface. Some reach the surface, but dissolve before they go very far across the surface. None are swept back under.


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## Kfactor (Aug 15, 2018)

I don’t think I would ever drill a bottom of a tank I heard to many story’s on it . If u get a leak your screwed lol


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## Deanna (Feb 15, 2017)

Kfactor said:


> I don’t think I would ever drill a bottom of a tank I heard to many story’s on it . If u get a leak your screwed lol


There is no drilling involved.


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## Cichlid-140 (Sep 28, 2018)

Kfactor said:


> I don’t think I would ever drill a bottom of a tank I heard to many story’s on it . If u get a leak your screwed lol


The holes are usually in an overflow compartment with limited volume. I for one like sump filters and wouldn't have one without a drilled in-tank overflow. Over the wall overflows can be problematic when recovering from power outages.

The reef keeping side of the hobby would be next to non-existent without this type of arrangement.


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## GrampsGrunge (Jun 18, 2012)

Probably apples to oranges comparison, also this was years ago, before high intensity fluorescent and LED lights were available.

My 29 gallon from '90-'95 used airline tube subsoil heating grid, it's flow powered by a small powerhead, took it's heat off the ballast coil of the Mercury vapor lamp, probably at most about 70 watts. 

I dissolved my D.I.Y. yeast/sugar 2 liter reactor CO2 directly into the outflow of the HOB. The filter outflow was near the powerhead driving the subsoil heating grid so I suspect that some of the CO2 infused water was driven through the heat grid system, to be released near the bottom of the tank at the outflow. Now I still suspect the long term success of that tank was because of the Laterite soil and heat tubes under the gravel, but for what little CO2 it did use the 29 gallon grew plants with a vigor I've not had luck with until recently with my 20 gallon yard soil tank.

I wonder if Deanna's set-up makes a weak inflow of fresh tank water through her gravel, in addition to keeping the lower level of the tank's water and gravel at a slightly lower pH with more CO2 concentration, which makes for more energetic Iron and Nitrogen cation exchanges possible at the hair roots making for efficient use of the CO2, while keeping the swimming areas of the tank at higher O2 levels from photosynthesis.


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## Edward (Apr 11, 2005)

Nice alternative delivering CO2 without pumps, diffusers, atomizers, reactors, etc.


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## Deanna (Feb 15, 2017)

GrampsGrunge said:


> I wonder if Deanna's set-up makes a weak inflow of fresh tank water through her gravel, in addition to keeping the lower level of the tank's water and gravel at a slightly lower pH with more CO2 concentration, which makes for more energetic Iron and Nitrogen cation exchanges possible at the hair roots making for efficient use of the CO2, while keeping the swimming areas of the tank at higher O2 levels from photosynthesis.


I can’t say that I’ve seen a dramatic improvement in plants using this new approach vs. my previous Griggs reactor and in-line diffuser, other than a slightly noticeable reduction in GDA (which may be the result of better plant health as a result of this diffuser). It is certainly, at least, as good as the other CO2 delivery methods I’ve used.

I suppose that it is possible that the substrate level introduction of CO2 could increase acidity at lower levels, with the attendant benefits, but probably not in my case. The reason is that I have my filter output wand placed down at the substrate level, just above the CO2 diffuser tube, pulling about 50% of the CO2 at a faster rate to the surface. However, most of the heavier plant mass is on either side of the filter wand, so it is still possible that the CO2 on either side of the wand is being held at the lower levels by the leaves and increasing acidity at those levels.

Interesting thought you had about ionic exchange between Fe and N, although I think it is broader than just the two ions. I have recently done two things that have caused a surge in health (may soon be looking at ways to slow growth down). Unfortunately, these two things were done nearly simultaneously, so I can’t say if the surge is due to one or the other, or both. These changes are:

1) I’ve made an attempt to balance the ions (cations balanced with anions) as much as possible. This includes most micros, all macros and GH / KH contributors. Doing so has forced me to adjust previous ratios of nutrients being dosed and has resulted in a drop in TDS.

2) With my new DIY doser, I’ve been able to dose micros twice / day and PO4 with urea twice / day. It’s possible that this frequency of dosing is helpful, as others have reported. It may also be that the urea is helping, although I don’t think it is substantial since I’ve tried it before and, since I use no biomedia in my filter, a fair amount of NH3 and NH4 has always been available to my plants anyway. Still, even if the immediate downstream of the urea isn’t helping, at least the additional NO3 it eventually becomes may be.

PS: I'm not a "her", but it's too late to change my user name.



Edward said:


> Nice alternative delivering CO2 without pumps, diffusers, atomizers, reactors, etc.


I’d tend to put this into the diffuser category, just a very long and adaptable diffuser.


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## GrampsGrunge (Jun 18, 2012)

George and Karla Booth had a long paragraph in the AFH mag article back in '92 about laterite as an assist for ion exchanges, The main driver of healthy plant growth , in the Booth's experience was adequate light, Enough CO2 and a energy source, (the Dupla heating coils) to help drive the catalytic cations exchanges at the hair roots.

I was in touch with George a couple years back they were selling their planted tank stuff from the 90's, their Dupla controllers, transformers and heating cables. Nice stuff but just too expensive for something I could DIY for myself.


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## Kfactor (Aug 15, 2018)

Cichlid-140 said:


> The holes are usually in an overflow compartment with limited volume. I for one like sump filters and wouldn't have one without a drilled in-tank overflow. Over the wall overflows can be problematic when recovering from power outages.
> 
> The reef keeping side of the hobby would be next to non-existent without this type of arrangement.


Every tank I have ever owned has a sump and if your wall one can’t get Syphon after a power outage u have something setup wrong . I would never recommend and over the top one ether I think if your doing all the work to have a sump go the extra and drill it


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## Cichlid-140 (Sep 28, 2018)

Kfactor said:


> Every tank I have ever owned has a sump and if your wall one can’t get Siphon after a power outage u have something setup wrong.


I agree. But setup mistakes are made from time to time. That's where the problems are. More to your point, I ran an Eshopps overflow as a Herbie on an Aqueon 90G for three years without issue. Like you said it's all dependent on proper setup.



Kfactor said:


> I would never recommend and over the top one ether I think if your doing all the work to have a sump go the extra and drill it


Or buy pre-drilled :grin2:

Now I think it's best to get back on the OP's topic.

To that end I have tried to reduce the mist with a post diffuser reactor of sorts by passing the effluent through 10' of 5/8" hose with limited but noticeable results.

20181202_175052 by pat w1, on Flickr

I've since added an additional 10' of hose all wrapped around a short length of 3" PVC with some improvement in the mist but it's still there.

My planting is over a 60" x 26" footprint and not dense at all. How do think that would impact the implementation?


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## Deanna (Feb 15, 2017)

GrampsGrunge said:


> George and Karla Booth had a long paragraph in the AFH mag article back in '92 about laterite as an assist for ion exchanges, The main driver of healthy plant growth , in the Booth's experience was adequate light, Enough CO2 and a energy source, (the Dupla heating coils) to help drive the catalytic cations exchanges at the hair roots.
> 
> I was in touch with George a couple years back they were selling their planted tank stuff from the 90's, their Dupla controllers, transformers and heating cables. Nice stuff but just too expensive for something I could DIY for myself.


Thanks, I read their theory on heated substrates (Aquatic Concepts). I’ve also seen countervailing studies the say it’s not beneficial. However, following their arguments for heated substrates, it seems that the benefit is due to water circulation through the substrate and faster biochemical processes due to heat.

I don’t think I’ve ever seen any studies that show that heat will help plants, but I have seen temperatures higher than about 80 dF slow down plant growth/health. In any case, if immersed plants can take all the nutrients needed via the water column (studies I have seen that support this), then faster uptake at the roots is a moot point. If I believe this, then root hair activity is unnecessary.

Concerning circulation through the substrate, this is the basis for our using under-gravel filters, which I did for several decades. This, too, has been discounted in recent decades and, once I removed my under-gravel filter, in a low-tech tank, I saw no difference in plant growth.

I'd be interested if any other members can offer support for the Booth's experiences.


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## natemcnutty (May 26, 2016)

Deanna said:


> In any case, if immersed plants can take all the nutrients needed via the water column (studies I have seen that support this), then faster uptake at the roots is a moot point. If I believe this, then root hair activity is unnecessary.


I wouldn't say unnecessary. Some things are taken up more efficiently and can be limited in uptake rather than luxury. I think it's pretty well understood that plants don't *need* rich substrates, but they can help in many ways when done right. Issue I have with them is yet another thing to worry about...


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## Deanna (Feb 15, 2017)

natemcnutty said:


> I wouldn't say unnecessary. Some things are taken up more efficiently and can be limited in uptake rather than luxury. I think it's pretty well understood that plants don't *need* rich substrates, but they can help in many ways when done right. Issue I have with them is yet another thing to worry about...


I think you're right about an active substrate assisting, rather than harming, particularly in aiding a perhaps inexperienced/inattentive dosing regimen of the water column. I have always been concerned about the depletion of that type substrate and how to compensate for what I suppose is a linear reduction in that depletion after a year or so and then, finally, either replacement of that substrate with new active substrate or full conversion to water column dosing.

Good point but, in my comment, I was actually thinking more about the nutrients being pulled from the water column down into the substrate, as per the 'looping' effect from the heat circulation resulting from the heating coils.


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## GrampsGrunge (Jun 18, 2012)

Deanna said:


> Thanks, I read their theory on heated substrates (Aquatic Concepts). I’ve also seen countervailing studies the say it’s not beneficial. However, following their arguments for heated substrates, it seems that the benefit is due to water circulation through the substrate and faster biochemical processes due to heat.
> 
> I don’t think I’ve ever seen any studies that show that heat will help plants, but I have seen temperatures higher than about 80 dF slow down plant growth/health. In any case, if immersed plants can take all the nutrients needed via the water column (studies I have seen that support this), then faster uptake at the roots is a moot point. If I believe this, then root hair activity is unnecessary.
> 
> ...


The thing about the substrate heat was it wasn't a fast flow like with a undergravel, George discussed this difference at length in his AFH mag article. As the chemistry of the water changed to reducing as it was heated and moved quite slowly past the heating wire so the ion exchanges could be catalyzed with out too much Oxygen present. The N and Fe both able to catalyze efficiently with the warmth and reducing ( more acid ) conditions. 

I talked at length with a local botanist about my tanks and she thought the results were compelling, as she was running a greenhouse and also noted that soil warmth with terrestrial plants is a large part of why plants grow faster in summer and why some greenhouses use base heated starting tables for starting tender plants.

Tom Barr claims to have tried the Dupla system, but from what I've discussed with George, Tom didn't use laterite, and his heat source, for expediency, was a heating pad on the bottom of the tank glass. The Dupla coils were suspended 1.5 inches above the glass bottom on special suction cup holders. Creating a grid that takes water close to the glass, upwards.

That Tom, as a biology scientist that should have attempted to be impartial, didn't use the same equipment and same same conditions as the Booth's makes this suspect.

I know Tom is a bit of a celebrity here, and has his own forum and website. This alone, to me, makes his ease at dismissing the Booth's success a bit alarming. 

I don't know of anyone else who has DIY'd the Dupla heating system. Mine was not thermostat controlled except for running as the light and ballast were on. I ran my tanks at 75 degrees except on the rare hot summer days when they'd creep up to 79.

The growth of my plants in these tanks surprised all my relatives, friends and acquaintances including a friend who was involved with the UofO Zebrafish cloning lab. The lady downstairs used to invite friends up from her retail greenhouse to see our tanks, We were a bit of a neighborhood sensation.

But as an aside Eugene, OR also had the the water quality chemist at Eugene Water and Electric Board's, Walterville Dam treatment plant was our Aquarium club president. Eugene's water was pretty exceptional for aquarium use.

San Francisco also has Hetch Hechy reservoir which is also of unparalleled quality. As was the water of Denver, Colorado, when the Booth's lived there. So there might be a correlation for the water out of the tap as a factor.


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## Edward (Apr 11, 2005)

When substrate heating cables were popular the most benefits had people who used them with aquarium heaters in cold rooms. It had something to do with the temperature difference between the substrate and the water column affecting the plants. When substrate was colder than water column, plants complained. But warmer substrate than water column or the same substrate temperature as the water column was growing plants just fine.


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## GrampsGrunge (Jun 18, 2012)

Edward said:


> When substrate heating cables were popular the most benefits had people who used them with aquarium heaters in cold rooms. It had something to do with the temperature difference between the substrate and the water column affecting the plants. When substrate was colder than water column, plants complained. But warmer substrate than water column or the same substrate temperature as the water column was growing plants just fine.


From our 29 gallon with substrate heat back in '92. We had decent heating in our apartment back then, our place never dropped below 68 degrees even in winter. The tank sat on a heavy Oak planked desk and the underside had a layer of bubble wrap between the glass and desktop.

What is being said isn't just the warmth of the substrate, it's the way the substrate is warmed with elevated cables and a layer of laterite below the cables to catalyze the N and Fe for the plant hair roots. The heat off the Mercury Vapor light ballast was probably not over 30 to 40 watts.












This tank ran for 4 years without needing any breaking down or deep cleaning of the gravel, I used a 2 liter DIY CO2 system in the HOB filter outflow and a small amount of terrestrial chelated micro nutrients. 30% water changes every two weeks. A gallon baggy of plant trimmings for our club's auction every other month came out of this tank, it was very productive. The Rotala, Hygrophila, and Java fern would overrun the tank otherwise,

I'm trying to recall the fish stocking was:

6 Flame tetras
8 Neons and false Neons
6 Glowlight Tetras
A mated pair of Nannacara Anamola
1 Clown Pekoltia


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## Deanna (Feb 15, 2017)

GrampsGrunge said:


> The thing about the substrate heat was it wasn't a fast flow like with a undergravel, George discussed this difference at length in his AFH mag article. As the chemistry of the water changed to reducing as it was heated and moved quite slowly past the heating wire so the ion exchanges could be catalyzed with out too much Oxygen present. The N and Fe both able to catalyze efficiently with the warmth and reducing ( more acid ) conditions.
> 
> I talked at length with a local botanist about my tanks and she thought the results were compelling, as she was running a greenhouse and also noted that soil warmth with terrestrial plants is a large part of why plants grow faster in summer and why some greenhouses use base heated starting tables for starting tender plants.
> 
> ...


Unfortunately, from my standpoint, your experience is of anecdotal quality. I doubt that this alone will be compelling enough to convince anyone to try it. However, I have seen tests with substrate that do offer reasons to try an idea. In your case, if you could put a barrier mid-way through your substrate, separating it into two halves, and then place the laterite under one half, place identical plants on both sides and report results (maybe via a journal), that would certainly spike my interest in trying it ...assuming, of course, that you can see positive differences.


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## GrampsGrunge (Jun 18, 2012)

Deanna said:


> Unfortunately, from my standpoint, your experience is of anecdotal quality. I doubt that this alone will be compelling enough to convince anyone to try it. However, I have seen tests with substrate that do offer reasons to try an idea. In your case, if you could put a barrier mid-way through your substrate, separating it into two halves, and then place the laterite under one half, place identical plants on both sides and report results (maybe via a journal), that would certainly spike my interest in trying it ...assuming, of course, that you can see positive differences.


A 29 gallon would be pretty small for doing a divided substrate, note that laterite is just one part of the heat cable system, the cation reactive area.

It's a shame that George's website is so dated. Linking to the discussion about cable heated substrates where they lay out the pro's and con's of substrate heating compared to UG and RFUG. From the section "What are the claims for them" makes some compelling comparisons. I was considering RFUG back then as one of the LFS owners thought it might work well for plants.

I do have experience with changing from UG to heated substrate, with my 50 long it took removing the UG filter, then burying silicone tubing grid drawing warmer water from a Hagen 150 watt heater to bump the plant growth. To save a lot of words, some images from 1992..


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## Edward (Apr 11, 2005)

GrampsGrunge, thank you for sharing your experience, very nice.


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## Deanna (Feb 15, 2017)

GrampsGrunge said:


> A 29 gallon would be pretty small for doing a divided substrate, note that laterite is just one part of the heat cable system, the cation reactive area.
> 
> It's a shame that George's website is so dated. Linking to the discussion about cable heated substrates where they lay out the pro's and con's of substrate heating compared to UG and RFUG. From the section "What are the claims for them" makes some compelling comparisons. I was considering RFUG back then as one of the LFS owners thought it might work well for plants.
> 
> I do have experience with changing from UG to heated substrate, with my 50 long it took removing the UG filter, then burying silicone tubing grid drawing warmer water from a Hagen 150 watt heater to bump the plant growth. To save a lot of words, some images from 1992..


Certainly intriguing. You may want to create a post to draw others in. It may be that it should be explored again.


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## GrampsGrunge (Jun 18, 2012)

Yeah I'm sorry Deanna, I spammed your thread.

I will start a journal on a heated substrate tank in the near future.


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