Day 3 of lowering TA with muratic acid and aerating. After 2.5 gal of muratic acid, addding 2-3 qt at a time twice a day, my TA is 200 down from 280. My PH has been staying at 7.2 the last 36 hours. I think a problem is approaching though, I will soon have to add water to the pool. This heat is taking water from the pool. I am afraid if I add water I will be right back where I started. I would still like to know if CH has to be increased in a vinly lined pool if you are going to use salt system and if hardness is added will it help keep other problems away?