Liner Problem

[chem geek]

By any chance, did you have Trichlor pucks in a floating dispenser in the pool? If the dispenser parked itself in one place, then the acidity and high chlorine level could bleach out and even weaken the liner in that area. [EDIT] Ignore what I just said. You said that this affected area is ABOVE the water line and I can now clearly see that from your pictures. [END-EDIT]

[EDIT2] Well, if I actually READ every post, I might learn something! You actually said you did use a floating dispenser so that would in fact produce very acidic (low pH) and highly chlorinated (high FC) water in the vicinity of the feeder when the pump was off. The only thing is that this would explain bleaching in the area where the water contacts the liner, but I don't see how that would bleach the area above the waterline. If the water level did ever get near the top (from rains?), then that would explain it, but you said the water level never got that high. [END-EDIT2]

Richard

[hrsdennis]

Hi, the picture looks to me like early stages of dry rot. It always happens above the water line. It takes many years before any serious damage will be done. Eventually the liner will become dry and brittle and start to fall apart. Many years down the road. The only cure is to keep the sun off it.

Later, Dennis

[Vinyl_Guy]

I can only add this:

When you say "I just opened my pool" do you mean after it being winterized and closed for the season? If it happened during the course of a a whole "winter" (or whatever the off season is in your area), it could be a lot of things. Just about anything could have slid down the pool walls at those locations and caused it. Liquid fertilizers being used on your lawn by a contractor, some one sealing your wooden deck with a chemical product, acid rain. Did anything like that occur in the area of the pool while it was closed?