My pH drifts relatively fast, 7.5 to 7.8+ in a day or 2. My TA reading is 90ppm. I have read pool school and it recommends lowering pH (7.0-7.2) to bring down TA to combat drifting pH. How low should I go with TA? I brought pH down Monday night to 7.2, aerating with waterfalls for ~1hr that night. pH this morning was 7.8 already, and TA is 90ppm still. I just lowered pH down to 7.2 again with waterfalls on. After 1 hour pH still at 7.2.
Is something else causing this? Pool built in 2006.