There's a small rust spot on the wall of my inground vinyl pool. The pool was installed last year. The screws holding one of the returns to the wall are rusting on one of the returns, on the other end of the pool. I can feel what may be a screw head behind the rust spot, but I don't see that there's a tear, and the pool doesn't seem to be leaking... Searching the site, I don't see anyone with a similar problem. I'm going to contact my builder (they have a couple other things to fix for me anyway), but thought I'd check here first. I need to find a Vitamin C tab and see if the rust spot goes away, but I'm sort of afraid of finding a tear under the rust and starting the leaking process.... Any ideas?