Quote Originally Posted by waterbear View Post
What was your FC BEFORE you covered the pool? Also, why did your CYA level drop? If the chlorine was low before you covered the pool borates by themselves won't prevent algae.
I'm sure the FC was fairly low after a day of swimming, I checked it in the morning and it was about 3ppm. The storm came in very quickly and if I had just added another bottle of bleach before closing, I'm sure I would have had no problem.
I added cya back into the pool, dropped the ph to 7.2 and shocked it to about 40ppm yesterday. This morning I could see the bottom in the 6' area while brushing. I expect to have it cleared out by tomorrow.
I don't know why the cya disappeared unless the algae already had started to grow and bacteria was consuming it. It had been pretty level for the last couple of weeks, then suddenly started dropping over the weekend.
I was really surprised how quickly it turned green and cloudy.