I have been searching the forum trying to find help on determining the source of my leak. I have been able to take a few steps but I have a specific question that I need to ask. First some details:
I am working on the pool in my signature. This whole season it was loosing an inch of water a day which I was refilling. Now that it is time to shut it down I just let it go. It lost its typical inch a day until it approached the 5 penetrations (2 fiber optic light fixtures, 1 vacuum connector, 2 return jets). Once it was near them the rate slowly dropped. When the water level hit them the loss stopped completely. So I know my leak is from one of these items.
I sealed around all of them using 4200 and I refilled to one of my marks. Unfortunately it lost water at the same rate. I have now purchased 2 test ball and I removed the eyes from my return jets and I have them inflated to 40 psi in the the 1.5" PVC that feeds the returns. I will know the results of that test in about 3 hours when I roll back the cover and check out my marks.
As i was thinking about this overnight I realized if I could cover each of the penetrations with some sort of waterproof sheet then I could refill to one of my marks and remove the covers one at a time to determine which one is leaking. This should work because the pool surface is a smooth fiberglass. But what to use to cover the openings?
The best I could come up with was a square of 3 mil plastic sheeting sealed by duct tape. I could pump out water until it was below the penetrations, seal each opening, then refill. My question is if the duct tape would keep the sheeting waterproof for the 5 or so days it takes to test. If not is there a better way to completely seal the openings so I can eliminate each one at a time? Is there some sort of semi-permanent, submersible, tape product? Or something to seal the edge of the plastic to keep water from leaking through?
I appreciate any insight.