# Diy Co2



## igot2gats (Aug 12, 2010)

Instead of setting up a yeast diy co2, would an air pump with an air stone do the same thing?


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## majerah1 (Oct 29, 2010)

No. That would only spread oxygen. You need carbon Dioxide.


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## jccaclimber2 (May 6, 2012)

If you want a one line answer Bev is correct, and honestly I would either tailor the plant life and lighting to thrive without CO2 (see my recent photos in the shrimp tank thread, none of those use CO2) or just get a pressurized CO2 setup (used in decent condition is fine).

If you want a more in depth explanation without reading "Ecology of the Planted Aquarium" then to quote a number of politicians "depends".

Normal water in a bowl will get you to around 3 PPM CO2. Decomposition will drive CO2 up. Plant consumption will drive CO2 down. Increasing surface movement will drive the CO2 *closer* to the 3 PPM value. If your CO2 is high, surface movement will lower it. If your CO2 is low, surface movement will increase it. The same is true with O2, although the numbers are different.

Per Walstad the CO2 in natural settings can go above 3 PPM with enough decomposition. While our aquariums you might see that in the morning if you had a dirty gravel bed and little surface agitation you won't at the end of the light cycle, and I wouldn't depend on it unless you go the full Walstad approach.

*What all that means* is that without injecting CO2 the airstone is probably beneficial. With injecting CO2 you will need to weigh if the increased O2 is worth the decreased CO2. If you're talking a pressurized setup the answer is generally yes.

Good water movement goes a long way. Aquariums aren't nearly as uniform in CO2 concentration as people tend to think.

*Something else to consider*: Even in a perfect setting the airstone is only going to drive you up to 3 PPM. With CO2 injection you can safely hold CO2 at 30 PPM with few risks. With good oxygenation you could go much higher, although you start to run the risk of gassing your fish in the event of a solenoid malfunction at some point.


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