I am wondering about these marks on the pool. They are grey and feel smoother than the plaster itself. I sort of suspect that the Polaris, which was in need of new tires when we bought the house, may have been damaging the pool surface. I can try to take photos but I really don't know how to post them.
I see that some of the neighbors have replastered... is that something that is done after 8 or 10 years normally? How do you know if it is necessary?