I have in-ground pool, the vinyl liner is 4 years old and l'm losing about 1/3 of an inch of water a day.
The pool company and the leak detection company and diver have been in and they can not find the source of the leak.
They've done all tests possible and isolated all parts and systems for testing. This is a total mystery.
The only thing that might be an issue is I'm told the area under the liner at the deep end is very very rough, likely due to some pebbles that have emerged from the earth over time (like rocks grow...?) or that were there before? and this might have created a problem. Anyhow, although there is no perforation, the liner there has a lot of wear and has likely thinned on top of those pebbles.
Has anyone heard of this problem before? Does that make sense? If that's a source of the leak, what would be the best way to permanently fix it?
Any other suggestions for id the leak?