Im new to this. We just bought our house in January. Everything was good until around March when we had some pump issues. The pool sat for 2 weeks till the part for the pump was replaced. After we got it back up and running, we noticed these patchey spots on some areas of the pool floor. It seems to be getting worse with time. (See pictures)
We have tried:
-Tried use a lemon and lime to see if that would do anything to see if we needed stain remover. Nothing happened. Acid from that didn't even make it budge.
-tried black algae based on Leslie Guy's recommendation. Did this treatment with some black algae remover with a wire brush. Nothing happened. Shocked with 4lbs of shock for 3 days in a row while using the wire brush. Nothing.
Any advice? Should I try the stain remover?