Thanks for the advice. This morning my pool still looks good. No visible algae. I tested this morning and my FC is 15. With my CYA level between 80 - 90, this is too low for a shock level, and too high for a normal daily level. Should I take the chlorine back up to shock level for another day or two? Currently my pool is holding levels overnight, and I would guess CC is around .2. (With a 10 ml sample I put the drops in for a CC test and the sample barely turns pink. And then I add just 1 drop of the next re-agent, and it immediately clears up. So it is definitely less than .5)

Since I live in a very hot area of the country, I am thinking I want my CYA levels around 75. But until my levels drop to that from splash-out and backwashing, I plan on keeping my daily chlorine level at 9. Does that sound right? (Current CYA 80 - 90)