Early this season my pH was a little low so I added 1 4LB box of borax. It moved from about 7.0ish to 7.6. I was happy.
But continuing over the course of the summer and now into September I've been adding pH down because the pH has gone to 8.0! Over the course of a month or so I've added about 4x what the bottle said to add in attempt to reduce my pH from 8.0 to about 7.4-7.6, but it's stubbornly held around 7.9-8.0.
I've been using an acid salt called Sodium Bisulfate(93.x%) which I've purchased at Lowes and/or Home Depot.
Is it normal to have to add so many times more chemical to reduce the pH?
What other things can I try? I obviously want to be careful because I don't want to overshoot and go too low on pH.
I have a 24K gallon IG Vinyl pool and use liquid CL.
FC this morning is 8.0, usually closer to 4ish but I recently shocked.
CC = 0 which is typical
TA = 100
pH = 8.0
CYA = ~50
Thanks in advance for the help!