Strange leak in pool


New member
Jul 7, 2020
Paducah, Kentucky
Okay this is a long story. I have an old (1980's I think) 20x40 inground pool with a 9 foot deep end. One skimmer, one main drain. The floor is concrete and the walls are fiberglass panels which (I assume) are embedded in the concrete.

Last spring I did something stupid. Had a lot of time off due to covid and figured I'd empty the pool paint it, fix it up ,etc . That was the first mistake. After partially emptying it the pool ended up "floating" up. We apparently have a very high water table. Not that bad, maybe 3 or 4 inches. I immediately filled it again and this pushed it back down somewhat.

The up and down destroyed the skimmer. It also left a few cracks in the bottom concrete as well as what appear to be hairline cracks in the fiberglass. The panels also have seams between them.

Removal costs were $5000 to $7000 so I though okay, let's see if i can salvage this enough to get a couple three more years of use out of it.

First chopped up the concrete around the skimmer and replaced that. It took a while but the skimmer is in. I haven't filled it in yet so it's there and there's a the pit next to the pool where it is. That pit always has water in it. Sometimes low and sometimes high. I figured at first it was ground water.

I also went around a put some AB pool putty on all visible cracks in bottom as well as any large cracks or openings in the seam of the pool.

But it's leaking somewhere and this is where I"m getting confused. I'm 99% sure no pipes are leaking or busted. I can run the pump for 3 or 4 days and it will drop to certain level and stop. I can also leave the pump off, plug the return jets (2 of them) and the skimmer and it will drop the same level.

But what's weird is that when I used a submersible pump to pump out the water from the pit where I replaced the skimmer the pool water level will drop as well. So there's still a leak somewhere.

Here's the real question. If a pool is surrounded by water that has leaked from the pool and/or groundwater will that prevent the pool from leaking from a place until that water drops to a certain level? In other words is the pressure from the water around the pool going to be sufficient to prevent leaking from a potential leak point in the pool?

I'm really at my wits end because it seems like I've pool puttied everywhere that even looks like it might be a leak.


Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Welcome to TFP! :wave: The only thing I can think of that seems to relate water loss and the pit would be a bad hydrostatic valve in the main drain - if installed. If the pool was designed to allow water to equalize back & forth to that pit due to the high water table, that's all I can think of. Do you have a hydrostatic valve in that drain?