pH: how high is too high?

Ronald U.

Bronze Supporter
Greetings, fellow travelers and pool owners. So my CSI is still fine with pH 8.3. But how high is too high as regards pH's effect on the pool's infrastructure? Thank you.
Today's readings: FC 5.5
TA 100
CH 200
CYA 30
Temp 62
Salt (from 9/19) 2400
Borate (from 9/19) 40


Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
High pH can lead to scale with a high CSI. No pH is too high if other factors in your water chemistry like your low CH and low water temperature offset it.

What is your CSI?

Ronald U.

Bronze Supporter
CSI according to Poolmath is 0.19. Scale will not occur, but does pH 8.3 begin to have a degrading effect on pool plumbing, pump interiors, etc.? Perhaps I should add that no one is swimming in this pool until spring returns.