What #s do you target ?
Some of your #s look realllly specific and pool store-y, how are you testing ?
The TA/PH roller coaster is a favorite and profitable game for the pool store. They often make people chase more ok than ok #s, and it spirals out of control.
For SWGs, we've found that TA on the lower side of in range (60) helps let the PH sit longer on the higher side of in range (7.8). For the most people, any 60-100 TA is equally fine as is any 7.x PH. Only lower the PH to a high 7 and the TA will likely stabilize on its own.