That is the scale you want to follow.. If it never made to 100 then your higher than that. You can do a diluted test if you want to find out how high it is, but with each dilution it's less accurate. so dilute by half multiple by 2 and so forth...Thanks again! Great point about rental pump vs. sand filter. The rental's $45 a day. Back wash to the street, provided the water is clear and free of debris and pollutants, de-chlorinated/ debrominated, measured on a pool test kit at “0” - anyone know how to prep the water before draining? Probably info in the above link; i will check. The face of the comparator says CYA then: 100 going on up to 30 at the top. My test got to halfway to 100 before black dot disappeared. The side has water fill lines, 1.8 being the first.
I'll have to look and see if I have little numbers on the side of my comparator too.. Now I'm curious, I never noticed them.