I just tested the water in my spa and if I read correctly all you test is the CH-PH-TA. (not sure if I read right)
Anyway here are my readings
Ch 10 should be 100
PH 7.6 anywhere between 7.4/7.6
Ta 40 should be 50
I did try to check the FC but I get nothing, the water is clear, does not turn color at all. What am I doing wrong. We have Sanitized the Pool and thought I was doing good.