Hi, just wanted to find some information on why my pool's pH is increasing from 7.5 to 7.9 after every night. I adjust the pH with muriatic acid every morning to get it down to 7.5 but when I test it the following morning its right back up to 7.9. I have a 30000 Gallong gunite pool with a water fall from the hot tub. I use copper ionization as my sanitization method. So far I have lowered the waterfall strength so there is less aeration but pH is still rising everynight. Do you think my copper ionization method or old sand filter (12 years old) has anything to do with this?