I've tested my CYA using the test kit. I find it far too subjective as it just depends on the lighting to make the black dot disappear. I was reading here that the higher your CYA the more chlorine was needed and if it was too high it wouldn't even measure.
So is this a valid way to know CYA is dialed in? I had zero chlorine. CYA was somewhere measured 50 to 80. Pool calculator indiacted I needed 9.5 cups of bleach to reach 4.0. I added that amount and chlorine was tested exactly 4. So I assume my cya is good as if I had too high of cya the chlorine would have measured lower or not at all? Perhaps I misinterpreted the article I read. My main concern is that CYA is too high at this point.