Hi there, I have a dark stain that appeared in my newly finished plaster. I did some research and what I found is quite unsettling. The pool builder office rep said they think it is a loose screw and they will have someone come out to look at it. I don't see where it could be any kind of screw unless she is thinking it dropped in the pool from the automatic cover install. The stain is right where the bottom of the pool curves to go up the wall. I sure hope it isn't from 
