Micon, the pH 'creeping' up is often sceen with SWCGs. Evan or Richard could give you the chemistry of why it happens. If I'm remebering correctly, lowering the TA to ~80 - 90 will slow the process and getting ~50 ppm borates in the water will also help (if you do the borate thing, you'll be needing to add a lot of acid to the pool, but once it's done - the pH should stay ~ where you want it). I'd hope that one of them will see this and expound on what I've said