My pool was finished last September 23. Last month I noticed large grey spots forming on the plaster. Go the water checked. Cleaned the filters. Changed the Nature 2. Called the pool contractor. He said he had never seen this in 40 years. Like I believe that! He sent out the pool service to check the water. Their service man said the plaster looked 20 years old. The owner of that company emailed that he would send someone out to look. Never showed. Now the contractor says he is sending out the plaster company. I saw that someone else had this issue a few years ago, but
I saw no outcome on the postings. I found an article written that said it could come from troweling the plaster too long when it is applied. Does anybody know anything about how to fix this condition. Its seems to be worsening.