So when I take the FC up to 20 ppm ----- How long do I keep it that high??

I still don't understand how swimming at 20 ppm can be OK --- If it bleaches your suit it can't be good for the various exposed organs, the skin being the biggest and most exposed. I think I understand the relationship of the CYA and the effectiveness of FC but it is not like it's (the CL) not there.

Also I do not have any CC so again how does this figure into the need to shock equation.