My PH goes from 7.4 to 8.0 Every night, If add PH decreaser in the morning to get it back to 7.3 /7.4 range it stays all day without going up but maybe to 7.5. But in the morning it will be right back at 8.0. I have a digital PH meter calibrated perfectly to 4.0 and 7.8 and double check with the...