Leak in fiberglass pool

Sep 7, 2019
Mansfield, MA
I have a 18x36 feet fiberglass pool that has a leak in the surface, but I don't know it's location. I already know some of the lines have leaks, but water level kept lowering even when level was below skimmer and return lines. Main drain has been pressure tested and is currently OK. Any ideas on how to locate the leak? There are no suspicious places and it would take many hours to use dye test around the whole surface.

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Welcome to TFP! :wave: For some pools, we would suggesting letting the water continue to drop, then where it stops is the water leak (level). But in your case (FG), you can't do that. We FG owners cannot afford to let the water get too low or risk a "pop-out" situation. A leak would assume to imply a crack which you should see. So if you don't see a crack, I would still be suspicious of that drain and or hydrostatic valve. I would consider plugging the drain with a rubber stopper of sorts and validating any further water loss. If it is the drain, leave it plugged. Your pool can operate just fine on a skimmer only. Hope that helps.