I have recently noticed these stains in the pool. What are they and how to remove them?
I should have noted that this is a fiberglass pool
This looks to be some type of scale. Have you tried touching it to see if it’s rough? If it scale, you will need some type of scale remover. The only other thing I can think is maybe the gel coating is deteriorating. How old is the surface?
The pool is 20 years old. I believe you are right. I think it is scale. I’m going to do some tests to determine if it is.