Ok, confirmed algae attempting to get a foothold in the pool. What I'd like to know is why the CC never showed more than .5ppm. Only clues I had were the odd lightly cloudy, and slightly elevated CC, with only those two overnight losses of around 4 FC. Water is now at shock level, and will be held there for the next two days.

Question for PoolDoc: In your experience has there ever been a relationship between low or high pH and the ability for algae to start even with FC being held within nominal levels of the best guess chart?

CYA is 70 - 90, so FC being held between 6 - 10. Do I need to keep it a bit higher range, like 8 - 12?

Also, could a mod change my pool chart data to show my having the K-2006?