After reviewing topic, "Raising Ph", I suspect borate level > 50ppm. I have used Borax to increase Ph all of last season and the start of this season. I prefer that my Ph be nearer 7.6, but no Ph increaser has been effective - I tried aerating overnight, too. I am not too concerned because all of my chemical levels are balanced and holding and pool is crystal. I read that reducing borate level requires replacing water. Is there a guide on amount of water exchange needed based on borate concentration and pool volume? Thanks in advance for your feedback.
TA = 100
TC = 2
Ph = 7.2
CA = 35
Vinyl pool; 16X32; depths 3.5' to 7.5'; Hayward 200 sand filter fed by skimmer and deep water drain, one return.