Quote Originally Posted by chem geek View Post
If both TA and CH were dropping, then it sounds like you might have a leak, assuming your fill water is lower in CH and TA than your pool and that you have auto-fill. Either that or you've got rain overflow diluting the water.

Leaves can have tannins that can be acidic which mostly lower pH and somewhat lower TA, but not by as much as you are seeing. I'll bet you are using test strips as those are notorious for inconsistent and incorrect results. Get yourself a good test kit, the Taylor K-2006.
No, I have a nice taylor kit I got from Leslie's that measures Cl, pH, TA, CH and CYA. Cost about $50 and does a nice job, so I don't think measurement is the problem. I think it was the storms that hit us in the Augusta area in late March and dumped lots of pine pollen and leaves in the pool. It seems to be stabilized now.