Quote Originally Posted by waterbear
I appreciate the technical explanations! They help me better understand what is occuring.
No problem. As you can tell, I enjoy this stuff.

The thread A Cheap Pool Cooler shows that two people with seemingly similar conditions can still get different levels of upward pH drift (and alkalinity lowering when acid is added to compensate for this pH drift). There is no question that all else equal, lower pH, higher alkalinity, and more aeration will cause more outgassing of CO2 which is why Ben's approach to lowering alkalinity tries to maximize two of these effects (obviously, making alkalinity higher so that you can lower it faster is, well, not the brightest thing to do). However, trying to predict the actual amount is really hard. There are formulas to approximate it, but they have so many parameters to put in that are really hard to measure that it's really not worth it -- it's much better to just get to "know your pool" and then you can use my graph as a relative guide using your own pool's behavior for a fixed set of conditions.