New(ish) pool owner
In South Africa, summer time over here now.
Had Fibreglass pool installed "last summer."
Salt Water Chlorinator and Heat Pump, black pool cover(the type that floats on the water with the bubblewrap look)
Maintained well over the summer. Didnt use at all during winter. Ran pump and tried to maintain as often as possible during winter
but noticed dark grey stains all down the sides of the pool (see linked pics)
Some say black algae, I say but it's a fibreglass pool and its not slimy or doesn feel like algae and it doesnt come off with scrubbing, at least not very easily. vey very hard to scrub off
Some say Cobalt Migration, whatever that is.
Some say your gel coating wasnt sufficiently applied.
These are "pool shops" Im walking into and describing the problem........admittedly having not shown the pics.
Can anyone help please and advise how i can get rid of this and prevent it.
Thanks so much in advance pleas try both links, they're the same pics. my first time posting so hope it works.