I've got a 15 month old plaster SWG pool that continues to have PH drift. About every 4-5 days I add acid to bring it down. I usually bring it down to the 7.2 range so I don't have to add every other day. Although the PH drift was much worse a year ago I''m still frustrated. I believe that the water is suposed to stablize around 7.6 - 7.8 for a SWG. Is that correct? The rise is slower once its gets higher. Should I let it go to see where it stablizes? My tester only goes to 8.0 so it's hard to read the higher PH levels.