Quick primer on how o2 levels affect co2 in the reef tank

brandon429 · Mar 15, 2015

Randy I had a question as to whether or not oxygen saturation reduces co2 in aqueous solutions by physical exclusion

im under the impression it does not...the partial gas pressure for co2 is what determines co2 levels and it functions independently of oxygen saturation at our common temps

From what I can see each gas has its own pressure moderator but I find it challenging to ponder why a soln packed with o2 would have room for any other gas

Perhaps size of the molecules in question determine saturation room sharing as well, can't wait to clarify.

we had been reviewing whether or not oxydators reduce co2 I think they do not, nor does any use of peroxide lower or displace co2, whereas co2 is controlled by input rates, temp, pgp, organic and inorganic sinks, surface boil, but not other gasses?

GreatWhiteTang · Mar 15, 2015

Following

Randy Holmes-Farley · Mar 15, 2015

The presence or absence of O2 has no impact on the solubility of CO2 in water.

They are not occupying spaces that can get filled up, and the spaces between O2 molecules in seawater is very large on the scale of a molecule. There are hundreds of thousands of water molecules for each O2 present in seawater, so the O2 is hardly perturbing the average environment of anything else in the water.

GreatWhiteTang · Mar 15, 2015

Does the OÂ² : COÂ² ratio effect toxicity of. COÂ²?

Randy Holmes-Farley · Mar 15, 2015

The answer to that could be different for every organism, since you are asking about how an organism responds to a toxin in the presence of a needed compound (O2).

I don't know that CO2 itself is usually toxic in seawater, since the concentrations are low. But higher CO2 means lower pH, and low pH can stress many organisms.

Overall, I doubt that raising O2 above normal levels will help reduce the stress of low pH, but I've not seen data on that question.

GreatWhiteTang · Mar 15, 2015

So COÂ² is the only one that would effect ph? I assumed that if OÂ² levels. We're higher ph would increase and that even though 0Â² and COÂ² aren't directly effecting each other... One could "dilute" the others effects rather than directly diluting one another if you increased them with a 1:1 ratio would ph remains the same. As they both rose and fell?