Quote Originally Posted by Rangeball
N=1, but in my and my pool's experience when I was aerating ALK rose along with PH until I got the ALK below 200. Even then, ALK only drops after I add the acid and let PH drop THEN aerate, and ALK remains constant.
Did you phrase that correctly? When you are aerating, your alkalinity rose along with pH? Or did you see it drop?

Before you got started with the aeration, you may have had a tendency to drift in pH due some acidic or basic process in your pool. It's hard to isolate the different pieces since it is an open system.

Richard