My cya level is getting pretty high from using pucks for the last 5+ years right now its about 70-80 what is a good number to hold the cya at? my pool is 38,000 gallon with a sand filter. I live in indiana & the pool does have an auto cover on it. I was going to start draining & refilling this weekend to get the cya down & i have quit using pucks. im currently in the middle of a slam. just wanting to know what a good cya number is?