Thanks for the information.

My chlorine was at 0 before I started.

I have a fiberglass pool and unfortunately they say I void my warranty if I ever drain it so draining to acid wash doesn't seem to be an option.

I'm so disgusted and defeated. I know they are metal stains because rubbing with a vitamin C tab helps remove them, the problem is the staining is ALL OVER... so it would take a year to rub the whole pool with tablets.