Here are my numbers after replacing about 30% of the water. I have a gunnite bottom and fiberglass walls that have been coated with epoxy paint. Approx. 24000 gallons, sand filter.
Free chlorine: 4
Combined chlorine: <.5
CYA: 35 (was 80)
I believe I need to bring up my alkality and hardness. If so, what should my goal be and is there a non-pool store product that I can do this with?
Please make any recommendations you see fit.
Thank you so much,