- Jun 22, 2014
- 52,051
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Are you referring to what appears to be those light brown and one darker color brown spot in the pic above? If so, I would try removing with products from lightest to most aggressive. For example: If clumpy, start with a putty knife > Magic Eraser > 1,000 grit wet sandpaper > 800 grit sandpaper > 400 grit sandpaper. When my pool was installed, the cement crew left all kinds of cement and grout lines running down the sides of my waterline. They weren't clumpy, just stains that were smooth. I used a combination of Magic Eraser and fine wet sandpaper to buff them out, so you might do a combination of the same. Whatever you try, always do a test area and let it dry if above the waterline to ensure you are happy with the result. Also an option, if you haven't done so already, is to contact your installer to let them know what a contractor did. Sometimes they will dispatch someone to work on it since you weren't personally responsible.Discovered during today's brush...won't budge. Any ideas?