Slightly over 50 is rounded up to 60.
Your CYA is approximately 120.
You will need to replace 50% of your water to get CYA down to 60-ish.
When doing a no drain water exchange, you will need to probably exchage at least 60-70 percent of your water to attain a 50% reduction in CYA due to mixing.
It's too hot in AZ to do a drain/refill this time of year.
One of the pluses for either methid is a reduction in CH as well.
Test your fill water for pH, TA and CH so you have a baseline. Chances are your CH will increase by at least your dill water CH yearly (probably more).
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