Waterline of a concrete pool, it’s a mainly grey coloured stain on a green pool tile. Tried CLR, oxcilic acid and lots of scrubbing. Didn’t make any difference. Help!!
297000cookie-checkRemoving greyish stain of waterline swimming pool tile. Could it be calcium silicate? Thank you
Not sure what that would be. But if you’ve tried acids, the next thing is to try an alkali. Try an oven cleaner. Spray on, wait a few minutes and see if it wipes off