Holes in Outer Edges of Vinyl AGP Liner
We've had our 24' AGP for about 7 years and are on our second liner.
When the first pool liner failed, because of small holes we couldn't find, we thought it was due to tree roots under the liner. Before installing the second liner we installed a Gladon "Perfect Pool Bottom" with foam coving to hopefully eliminate these problems. We had no problems for the first couple of years.
This past winter most of the water slowly leaked out again. This spring we were able to find a couple of small holes (less than 1/8" diameter) and patch them. One of the holes was definitely made from something sharp pushing up through the liner from the bottom. To prevent this from happening again we removed the "Perfect Bottom" but left the foam coving in place.
While working under the pool liner we found more small tree roots had grown under the pool. Nothing that I would consider large or problematic. I cut the tree roots as far under the foam coving as I could and dug a very narrow trench with a putty knife and put a small amount of rock salt in the trench (only in the trench) to deter the tree roots from growing under the liner again. I closed up the trench, covered with sand, smoothed everything out and started putting water back in the pool.
With about an inch or two of water in the pool I pushed all the wrinkles out of the pool liner and everything looked great. We finished filling and opened the pool, after several weeks we noticed the water level
was dropping again. Upon investigation we found a 1/8" diameter hole near the foam coving in one of the areas we put the rock salt. Since then we've found about 6 more holes of roughly the same size in roughly the same places near the coving, where we put the rock salt.
Is it possible the rock salt is somehow eating / making these holes in the liner?
Thanks for your time, Mike
It's impossible for me to say what is causing the holes without being there. But here are a few things that might help.
I doubt the salt has anything to do with it, just does not sound likely to me.
The most common cause of holes in a liner are due to cleaning. Automatic cleaners can leave pin holes across the bottom, or in one particular area if that's where the cleaner spends a lot of time.
A manual vacuum will leave little 1/8" vertical cuts around the outer edge of a pool, usually where the bottom meets the wall. It's possible also the holes could be where the liner meets the cove, if the vacuum bumps into that area.
If that does not help be sure to get under your liner before you decide to change it. With the pool empty release the liner in a small area and get in behind it. Have a helper pull the liner back to the wall leaving you in the dark. From under the liner you should be able to see all the holes. There is a lot you can learn under a liner, and most of time you can determine the problem and not let it happen again.