CO2 O2 and aeration

[gupp]

I did a search and couldn't find this topic covered specifically. I hope I'm not repeating a previous discussion.

Tom says in another post "CO2 goes into and out of solution with water very easily"

and there is more CO2 in air than water, so wouldn't using aeration, which just pumps air in to the aquarium, put more CO2 and O2 in to that aquariums water, than an aquarium with no water movement?

I may be mistaken because my memory is less than perfect, but wasn't Ole Pedersen saying in his talk a couple years ago at the AGA convention that creeks with a lot of rocks and surface movement had higher levels of CO2 because of that. Wouldn't the same be true in an aquarium or have I missed something?

Not that I plan on starting to add air or filters or any of that sort of thing on my aquariums, lol this is all hypothetical conjecture.

 

[VaughnH]

Because water is a liquid, the CO2 concentration in water is expressed in parts per million - the CO2 is dissolved in the water. But, air is a gas, so CO2 is not in solution in air, just a component of air, and the concentration is expressed in partial pressure (normally) or percent. The CO2 concentration we want in our tanks is many times higher than that which can be obtained by mixing air with water, at least ten times higher.

 

[gupp]

I'm sorry I worded that poorly. Hypothetically if you had a 10 gallon tank sitting full of water and a 10 gallon tank sitting full of water with a running small bubble air stone, which would have more CO2 in it?

Wouldn't the one with the air stone because it would create more area where the CO2 could dissolve in the water?

 

[VaughnH]

If the tanks had no plants or other consumers of CO2, they would both have the same concentration, that which is in equilibrium with the air. If they had plants, the one with the airstone should be able to maintain at least a slight edge on ppm of CO2 in the water. Just my opinion.