Stain ID and removal

[Peeper]

Stain is approx 1/4 around pool. Have had it for 2 yrs. This year it is getting darker. Have tried liq chlorine on rag, magic eraser, plain cotton rag. Get very little off. Tried vit C in sock and did nothing. Water is clear and balanced. Thoughts?

 

[mknauss]

Is it sticky? Is it raised? Is it all above the waterline?

 

[Peeper]

Is it sticky? Is it raised? Is it all above the waterline?

Not sticky. Not raised. All above waterline.

 

[mknauss]

Sun damage? With it being above the water line, I do not see how it is tied to the pool water. Do you keep a cover on the pool?

 

[Peeper]

The same color stain is also on the cord to our Dolphin automatic cleaner and that stain is sticky.
The pool is covered at the end of the season.

 

[mknauss]

My first thought was build up from sunscreen, hair products, etc. But it is above the water line. That is odd. I asked about cover as if you had a solar cover, it could concentrate heat, etc on one area of the liner.

 

[Peeper]

No solar cover.
What do you recommend to remove a build up of sunscreen, hair products, etc?

 

[mknauss]

I use Simple Green and a scrub sponge.