Thanks a ton you guys. I think I am really close. My Alk is 120. Ph 7.2. I think I need one more gallon of acid. The last one I added didn't seem to do much. I plan to bring alk down to 100 based on Ben's sticky (http://www.poolforum.com/pf2/showthread.php?t=191) and the fact that my fill water is HIGHLY alkaline.

So you are saying once I get Alk down, that it's ok to leave Ph at 7.2? I've aearated for two days straight with fountains at Alk 120 and ph at 7.2. I don't think Ph will rise anymore with just aeration. At least not with my fountain set-up. so I'll lower one more time, get Alk at 100, aerate to bring ph back to 7.2 and leave it alone.

Is there any compelling reason to bring my Ph up to 7.4-7.6 from 7.2? Honestly, it just never ever moves from 7.2 for long. so I'm not too worried about it being lower that 6.9 with my liner. In fact, even when adding a gallon of acid at a time it never went below 7.0. Maaaaybe it was 6.9 for a couple hours, but that was it.

Thanks again!
Jennie