Since the higher your CYA, the less effective your FC is in fighting algae etc and you need higher chlorine levels if you need to slam does high CYA protect swimmers who may be allergic to chlorine and or may not want their bathing suits faded from high chlorine levels? I have read instructions in the past, on shock products, that indicate not to go into the pool when chlorine is more than 5 ppm. If my CYA was 100 my FC goal would be 5 to 13 ppm but if I had no CYA and had an indoor pool then my FC goal would be 1 to 3. Would both of these scenarios have the same effect on people, bathing suits and vinyl liners? Thanks. Just curious.