High Ph in new plaster pool

[TIDE500]

We put in a new 35,000 gallon plaster lined pool last September. The ph constantly goes up and I use muriatic acid to bring it down. My question, is it normal to have to put in a gallon of acid every second or third day. The ph will go down to about 7.4 and in a few days up to 8.0 or higher. I know that it was going to use acid till the plaster cured, but I think i'm passed that point.
FC 3 Salt generator
TA 90
CA 250

Thanks

 

[Richard320]

Welcome!

Answer: Yes. 35000 gallons is a pretty big pool. The TA of 90 isn't helping, nor is the SWG. Just keep knocking it down. You might want to target 7.2 pH. It'll buy you an extra day between doses, and the CO2 outgassing is faster at lower pH, so the TA will drop a little quuicker.

 

[TIDE500]

Welcome!

Answer: Yes. 35000 gallons is a pretty big pool. The TA of 90 isn't helping, nor is the SWG. Just keep knocking it down. You might want to target 7.2 pH. It'll buy you an extra day between doses, and the CO2 outgassing is faster at lower pH, so the TA will drop a little quuicker.

Should I raise the TA ? Is this an excessive amount of acid?

 

[pooldv]

No, higher TA contributes to PH rise. Lower PH helps to slow PH rise. Adding acid repeatedly to lower your PH will also lower your TA, as low as 60 is fine.

 

[Richard320]

Should I raise the TA ? Is this an excessive amount of acid?

No, not excessive given fairly new plaster, high TA, SWG and a large pool. My plaster is close to ten years old and my pool is half the size of yours and I use about a quart a week. And I don't have a SWG.