So it looks like my CYA is almost 30 ppm now but not sure cause test tube starts at 30 and I can still kinda see outline of black dot.

But I just wanted to confirm that based on the Best guess chart, if I my CYA is between 30-50 ppm. Then I want to have the free chlorine between 3.0 and 6.0 ppm?

Think i need to get that FAS-DPD add on kit then cause mine only goes to 5.0.

Also If I wanted to support the forum, is there a link i could click to purchase the appropriate unicel (A) filters on Amazon?

Thanks again. You guys are amazing.