dull fiberglass wall above waterline


New member
Jan 14, 2020
so I have read many comments about how to make your fiberglass pool wall shine again,I tried car wax,sponge,mr clean scrubber. A fiberglass restoring gel. But it looks good till the next day,then I have a light black or dark ring above the water line. Is there something I should not use to scrub so fiberglass wont scratch? And what cleasner do I need,

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Welcome to TFP! :wave: A dark, almost gummy line around the water line is often signs of what we call a scum line. This is much different than what could be seen as an faded or oxidized area above the waterline from the sun's UV constantly beating on the exposed gelcoal. Our pool may see a dark scum line in a corner or two once or twice a year. Just sort of happens. I remove it with something like a Mr. Eraser. For faded gelcoats, you can try an aftermarket fiberglass cleaner, sometimes from a marine center. Some folks may even try some 1,000 grit wet sandpaper. As with any method used, try in a small area first to see if you like the results.