[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: CO2 and O2

> Tom, you said "We pump CO2 gas and dissolve it well going far beyond the
> saturation level."  I'm not sure what you mean by this --

Ambient air. If you let the tank stand there without any biota, CO2
injections etc it will reach an equilibrium with the air.
All I was saying is that above that, CO2 will be going *out* of the solution
relative to the air. At 100% O2 saturation or CO2 saturation you are at a
steady state(no net flux of in/out of either gas).

Adding a ton of aeration to a tank that has 14ppm of O2 at 77F will _lower_
the O2 level(O2 goes out). Or if you let it stand long enough it will
equilibrate with the air provided no new primary production is producing
more O2.

with O2 we get 
> supersaturation and pearling (around 10 ppm),

You can get both of these at less than 10ppm.

> but water can hold *far* more
> dissolved CO2 than is safe for our fish. I thought you can get in excess of
> 1000 ppm CO2 into (seltzer) water.

Yes you can add more.
O2 also for that matter. It'll kill fish good also.

> Or do you mean (plant) saturation with
> regard to their carbon needs?

Ambient air only(CO2 and O2). These questions always get folks tangled up
and thing never come out clear. Sorry it was early:-)
Plant's carbon needs is a bit more thorny. I simply set my tank's at
20-30ppm. That works for me.
Tom Barr
> Jared