I just did it with 1/2 pool water, 1/2 tap and at 60 the dot disappeared making my CYA 120! Now that sounds right!!! I need more FC if this is the case.

So doing the CYA test. I slowly added the water...waiting for the dot to disappear. At one point (80ish) I thought it disappeared but if I waited a second and killer squinted and strained my eyes I could still barely barely barely see the dot. Am I wanting to go past that point untill I 100000% cannot see the dot anymore or should I have stopped at 80?

Thanks everyone!!!