I have a new pool in ground pool [plaster with quartz additive] , about 1 year old. Our water is extremely hard and alkaline. Chlorine is fine. pH always increases up to 7.8 each week despite my adding 2 gallons of 15% muriatic acid weekly. I have probably added 40 gallons of 15% muriatic acid over the last year. Total acid was about 240 and I am finally able to bring it down to about 150-160 [after 8 gallons of acid] but no further.
Is this from the plaster installation or from the initial pool fill water alkalinity or from some other issue? I have a cover on the pool, so I do not believe new autofill water is contributing to this.
Any suggestions how to bring this down once and for all so it doesn't keep creeping up?