This morning's FC/CC reading @ 0.5 measurements showed a barely discernible CC level (meaning that I almost didn't have to add 1 drop of reagent to clarify the water during the CC test it was already so clear -- though adding one drop did seem to improve the clarity just a smidgeon). I've noticed over this week that sometimes the CC level turns a slight shade of pink after adding 5 drops of reagent following the FC test, and sometimes it's a barely discernible shade a pink (meaning less than a "slight shade of pink"). Is it normal for CC levels to bounce around slightly? What causes the CC level to drop if you're not shocking your pool?