"aquarium", I must apologize. Though an alkalinity of 100 and pH of 7.4-7.5 works fine for my pool, your pool may be very different and need different parameters. What I do know is that you will outgas more CO2 if you have lower pH and/or higher alkalinity so if you want to keep your pH closer to 7.2, then you will need to keep your alkalinity down so that the amount of aeration in your pool (which may not easily be changed) has the pH rise slowly enough for your tastes.

This whole issue has given me the thought of another graph I can construct that will show the relative CO2 outgas rates as a function of alkalinity and pH. I cannot give absolute rates since that's a physical aeration process that will be different for everyone's pool, but at least I can show the relative effects. I'll put this in the China Shop under my Pool Water Chemistry thread.

Richard