chlorine

[aylad]

You've been trying to get it up to shock level in order to burn off the CCs. If you can test the chlorine tonight, and test again in the morning before the sun is on the pool, and not lose any chlorine in the meantime, then you can let it fall to normal chlorine levels, which for a CYA of 80 means 5-10 ppm.

[madwil]

what aylad said...
1 gal bleach in 20k gallon pool only adds 3 ppm FC, so you've added 15ppm. some of that was used converting CC, and some lost to sun, so 11.5 is about right.
If CC <1 and FC holds, you don't need to shock

[mrs.rainbow]

Thanks for the help!