pink algae and other problems

Water loss due to evaporation won't bring your CYA down--it just concentrates the CYA in the remaining water in the pool until you refill, then the refill just dilutes it back to the same level it was before the evaporation. If you're wanting to bring the CYA down, it'll have to be done by water actually removed from the pool--splashout, backwashing, draining to waste, etc.

Janet

Thanks for that piece of info. So can I safely drain half my pool even if I have steps into my shallow end? Also any thoughts on "Yellow Out" vs "Pink Treat"

So long as the steps are fiberglass, and not liner covered. If the steps are liner covered, you can't drain at all.

Yellow Out is ammonium chloride, which creates chloramines. I don't know what Pink Treat is, but most of United Chemical's products are sodium bromide + detergent type phosphates. Make sure you know what you're in for, before you use them!!