Ok last pm about 10 pm
FC 17
CC 0

This am
FC 15
CC less than .5 (it wasn't even pink, just not exactly clear either, cleared completely with 1 drop)

Water looks perfect. I will vacuum, backwash, and keep chlorine at 15 again tonight. What else should I be doing? Is CC a byproduct of using the pool? Should I be concerned that it keeps reappearing? Should I be concerned about the 2ppm overnight chlorine loss?

Thanks for all your help.