Pool has a case of ring around the collar...

[czbrody]

I switched from the Frog System to TFP system. I am using liquid chlorine and got the TF 100 kit and have been testing with that. The pool water is crystal clear. Numbers: FC 5. CC 0 pH 7.2. TA 60. CYA 60. CH425. I am clueless as to what it could be. It is just around the perimeter of the pool. Not in the middle. I put a chlorine tab on it and it did nothing. I put a vitamin c tab on and it did nothing. Doesn't rub off or brush off. Any ideas or suggestions? Thanks in advance! Cheri

 

[ajw22]

Try Magic Eraser on Pools - Further Reading

 

[YippeeSkippy]

Did you used to walk around the pool pouring in chemicals? That's my first guess. Copper stains being my next guess since you had a Frog but not normally quite so....localized? <shrug>

How long did you hold the sock full of crushed Vitamin C tabs to an area of stain?? Like 5 minutes??

Maddie