I have always had to fight to lower my Ph from 77 down to 75 with about 7 ounces MA weekly. No biggie. Last Saturday I bought a solar cover, heated the pool from 75 to 85 and started covering the pool at night. (heater off) It has been maintaining temps from 84 to 90 on its own without the heater. Tested Ph yesterday and it was DOWN to 7.3 . It's NEVER went down. Always up. Nothing else has changed. Can the temp or the cover cause that change?