# Compressed air for Co2



## stcyrwm (Apr 20, 2005)

Tom Barr's "New CO2 revelations", see thread:http://www.aquaticplantcentral.com/forumapc/showthread.php?t=9586 led to a discussion (on another board) about using air which is .03% CO2 to get CO2 to plants. Shalu has been doing this with an air pump fed into a HOB. Tom suggested and I want to try using compressed air fed into a ceramic diffuser or something else to create microbubbles that would then be dispersed by a powerhead, the same as he's doing with CO2.

I'm going to start putting this together tomorrow and would like to hear any feedback. I have a compressor and a tank so that parts easy. Pressure would be low enough that regulating pressure should be easy but I'll have to research that a little bit. Then it's a matter of creating the microbubbles to disperse. I doubt anyone has a ceramic diffusor locally but I'll check. Another idea is Duetto with aerator.

Open to ideas and suggestions........

Bill


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## hoppycalif (Apr 7, 2005)

To start with, air does not contain 30% CO2. It contains around .003%, substantially less. Air is about 70% Nitrogen, almost 30% Oxygen, and traces of other gases, including CO2 and H2O. So, using compressed air will not deliver much CO2 to the plants. I think I am missing something here???


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## Laith (Sep 4, 2004)

Air is almost 79% Nitrogen and almost 21% Oxygen. The rest is trace gases, including CO2.

I don't see what more you would get out of using a compressed air cylinder than you would using an air pump?


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## stcyrwm (Apr 20, 2005)

Sorry If I had quoted right it would have been .033%.......... I corrected earlier post.....


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## Simpte 27 (Jul 16, 2004)

I don't see the reference to using compressed air in the article.


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## stcyrwm (Apr 20, 2005)

Simpte 27 said:


> I don't see the reference to using compressed air in the article.


See: http://www.plantedtank.net/forums/showthread.php?t=21340


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## Simpte 27 (Jul 16, 2004)

I've read the article before (both here and on Tom's site) and I still see no mention of compressed "air".


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## stcyrwm (Apr 20, 2005)

Simpte 27 said:


> I've read the article before (both here and on Tom's site) and I still see no mention of compressed "air".


I hope this is OK to copy from another site. If it's not please delete.

This is from the thread on the Planted Tank board:

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

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

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

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

Dissolving O2 is not the goal, getting the bubbles very small and onto the plant leaves is the goal." End of quote from Tom

Hope this helps. Bill


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## Simpte 27 (Jul 16, 2004)

Now I see what you are saying.


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## Laith (Sep 4, 2004)

I may be slow today  ...

How is compressed air any better than an air pump? Both use the same air...


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## SnakeIce (May 9, 2005)

higher pressure able to force air through an object that would create smaller bubbles. The difference between a bubble wall and champagn bubbles that waft about.


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## JimM (Aug 26, 2005)

I don't see the point in using compressed air vs compressed co2 to deliver co2 to plants.. Wouldn't it be a lot less efficient and require the same equipment? Is everyone killing their fish with compressed co2?


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## stcyrwm (Apr 20, 2005)

JimM said:


> I don't see the point in using compressed air vs compressed co2 to deliver co2 to plants.. Wouldn't it be a lot less efficient and require the same equipment? Is everyone killing their fish with compressed co2?


I don't think you'd need the same kind of regulators or tanks on air because of the lower pressure of most air tanks. I'm assuming pressurized CO2 is much higher than the 100 psi of most air tanks. Is that right?????????

You could also fill the tanks yourself with a compressor or go to the gas station. Downside is they probably wouldn't last as long either.

You could also throw away the KH and pH testers. There will probably be other issues though related to circulation, aesthetics and maintenance.

It was just an idea anyway, and some of us like to experiment. First question is whether it would even work or not. I've been fiddling around with it but there are no good local suppliers for the kind of diffusers Tom was talking about so I bought a Duetto 100 and I'm using the venturi to get the fine mist of air in the tank.

The tank I'm experimenting with had been a 2 wpg non CO2/Excel tank but I felt like the real test would be whether this would keep algae down in a high light tank so I almost doubled the lighting. So far plants have responded with accelerated growth and color. I assume that would have happened with the increased light regardless. The real test will be what happens with algae? I have some bba on a log so I will be monitoring it to see if it spreads, stays stagnant or dwindles. If this goes well I will set up some test tanks and do comparisons.

Bill

PS
If anyone wants more details I started a journal today which I think everyone can access on my user page.


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## awrieger (May 20, 2005)

stcyrwm said:


> I want to try using compressed air fed into a ceramic diffuser or something else to create microbubbles that would then be dispersed by a powerhead


If you have fish, you run the risk of micro air bubbles entering their bloodstream via their gills and causing nitrogen supersaturation.

There's frequent info on wetwebmedia about a situation that should be avoided where air accidently leaks into a canister filter and is churned into micro bubbles by the rotor which will supersaturate your tank and kill your fish. A situation you actually planning to create! 

If you have no fish though, it wouldn't make any difference I suppose.


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## dennis (Mar 1, 2004)

Don't change to many variables at once. I would not increase the lighting yet, just start adding the air and do so consistantly for 2-3 weeks. Observe your results and then if you want, try higher lighting. I would not double my lighting all at once though. Even with well balanced, healthy tanks a sudden large change like that will often trigger small algae outbreaks or nutrient imbalances due to unexpected increases in growth patterns.

I can't imagine running a 4wpg tank w/o CO2 in the high ranges. Many people have algae issues in such high light tanks even with 30ppm CO2


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## stcyrwm (Apr 20, 2005)

awrieger said:


> If you have fish, you run the risk of micro air bubbles entering their bloodstream via their gills and causing nitrogen supersaturation.
> 
> There's frequent info on wetwebmedia about a situation that should be avoided where air accidently leaks into a canister filter and is churned into micro bubbles by the rotor which will supersaturate your tank and kill your fish. A situation you actually planning to create!
> 
> If you have no fish though, it wouldn't make any difference I suppose.


I looked through wetwebmedia and it seems to be more of a problem with corals. I couldn't find anything definitive about fish. If you have any specific references I'd appreciate reading them. I do have fish and I don't want to harm them. If anyone else has any info or experience I'd like to hear it.

When I used to have diy co2 on this tank the filter used to spit microbubbles the last few hours of the light cycle from oxygen saturation and it was never an issue then but this is a more intense level..........

Thanks, Bill


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## stcyrwm (Apr 20, 2005)

dennis said:


> Don't change to many variables at once. I would not increase the lighting yet, just start adding the air and do so consistantly for 2-3 weeks. Observe your results and then if you want, try higher lighting. I would not double my lighting all at once though. Even with well balanced, healthy tanks a sudden large change like that will often trigger small algae outbreaks or nutrient imbalances due to unexpected increases in growth patterns.
> 
> I can't imagine running a 4wpg tank w/o CO2 in the high ranges. Many people have algae issues in such high light tanks even with 30ppm CO2


Dennis,

You are right of course. I'm being impulsive, but if I could run 4 wpg without CO2 then that would be something. I'm not too concerned with this tank. I've kind of proved a point to myself about growing plants with 2 wpg, excel and no CO2. Everything in the tank is doing fine - riccia, glosso, limnophila aromatica, bacopa australis, cabomba, hygrophila corymbosa, pogostemon stellatus and ludwigia brevipes. There's even a decent amount of color on the "red" plants.

I'm kind of at a point though where I want to see the red ones really pop with color. Obviously the next logical step would be to go pressurized CO2 to accomplish this. I may end up doing that, but in a way this tank has always been a little bit of a lark for me, and I guess this is a way of carrying that lark out a little longer..........

I may also explore what it would take to really do an experiment. I imagine setting up a few smaller tanks and like you said only altering one variable at a time.

Thanks, Bill


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## neonfish3 (Feb 12, 2004)

stcyrwm said:


> I looked through wetwebmedia and it seems to be more of a problem with corals. I couldn't find anything definitive about fish. If you have any specific references I'd appreciate reading them. I do have fish and I don't want to harm them. If anyone else has any info or experience I'd like to hear it.
> 
> When I used to have diy co2 on this tank the filter used to spit microbubbles the last few hours of the light cycle from oxygen saturation and it was never an issue then but this is a more intense level..........
> 
> Thanks, Bill


Look up Gas Bubble Disease. Heres one reference: http://www.reefs.org/library/article/cripes_kowalski_phipps.html

I caused the problem to my fish once by adding water out of the tap that was cooler than my tank water. The gasses came out of solution all at once and caused 3 fish to die and one with pop-eye. Some of the fish had bubbles under their skin like this:









All the fish with the bubbles under their skin made it through,the bubbles went away after about 5 days, the one with pop-eye still has a bulging eye
I'm not trying to scare you away from the idea, but the condition is real and possible.


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