Hello. New to forum.
Getting ready to close my pool this weekend, but within the last few days I've gotten white spots on the bottom of the pool about 4-5 inches in size. They do not brush away.
Don't know what these are. Have had metal staining over the season, but took care of that with metal out.
I am concerned that if I let this go, it may become a bigger problem. Any ideas?
Light Blue fiberglass pool