Fiberglass Pool Leak - Can't find

Aug 26, 2015
9
starkville, ms
Hi - I have a fiberglass pool leak and I can not find the leak. Any help would be greatly appreciated.

1. Leaks 6 inches per 12 hours if pool is running or not running. Doesn't matter, still leaks
2. No bubbles in lines, Pump stays primed when on and off.
3. Turned off the pump and allowed to drain. It drained below all jets and lights except the main drain. Where it stopped, I could NOT find a leak in the Fiberglass shell. The pump stayed primed.

What am I missing? Thank you!!!
 
Hello and welcome! Well, if the draining stops at the return jets, lights, and/or skimmer, it has to be related to one of those areas. Have you ever tried a little food dye? Squirt a small bit near each area and see if it gets "sucked-in" to that spot. That may help you isolate so then you can figure out what to do next. Keep us posted. Welcome to TFP!
 
Based on your examination, the main drain sounds like the issue. But, how is the pump still primed with the level below it? If no cracks in the shell, the main drain line seems obvious. Usually fiberglass pools have main drains that will be a threaded fitting: usually 1 1/2 or 2" and will take a plug. Is that something you can do? And if you can, are you're skimmer and main drain lines have separate shutoff valves?
 
I have separate valves for my skimmer and my main drain. Check to see if you have two lines coming up from the pool to the one pipe going into the pump basket. If you're not sure maybe you could post a pic?

When my pool was installed the PB made a strong point to not let kids stand on the small safety covers over the main drains. Said it was a PITA to fix if broken... any chance someone stood on one with their toes like a ledge?
 
Thanks YipeeSkippy - yes, I do have two lines coming up from the pool and one pipe going to the pump basket! So, I want to plug up the main drain and then have only the water coming in from the skimmer?

Not sure about the small cover of the main drain - of course, there is a possibility that someone stood on it.

Thanks!
 
Thanks YipeeSkippy - yes, I do have two lines coming up from the pool and one pipe going to the pump basket! So, I want to plug up the main drain and then have only the water coming in from the skimmer?

Not sure about the small cover of the main drain - of course, there is a possibility that someone stood on it.

Thanks!

Do you have a valve (turn handle) on that pipe (where the two pipes are joined) that allows you to turn the skimmer off and only draw from the main drains and visa versa? I would turn it off to the main drain side and only have water going to the pump from the skimmer. (sidenote: make sure your skimmer's water level is high enough so you're not sucking air). Then monitor for the leak and see if isolating the main drain off cures the leak.
 
I'm curious to see how this one turns out. The original description indicated water kept leaking, even when pump (that never lost prime) was turned off, but stopped when it got to the return jets and lights (which also means skimmer). So if we're putting any money down on this one, mine if on one of those areas, otherwise the water would still be leaking right now if it was the main correct? :confused: So please keep us posted. I hope you get this resolved soon.
 
In preparation to plug the main drain, I wanted to ask another question. I have attached a picture of the level where the water stopped leaking. It's sat at this level for about 6 hours. Still below water is the light (I was wrong in my original post) and main drain. Therefore, the leak could not be in the light or main drain, could it? I will still plug up the main drain if y'all think that is the route to go. Thank you!!!!
IMG_9590.jpg
 

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Hard to tell from the pics, but I think you can rule-out the skimmer since the water kept dropping below that. I would look to any of the items right at that new water line after it stopped dropping. But from the pics, the water appeared to keep dropping even past the return jets huh? Not sure if the force of water pressure on any submerged items (light or main drain) would have an impact. Did you ever try to food dye test?
 
Texas splash - I haven't tried the food dye test. I will try that! The water does keep dropping past the return jets. The problem is that there aren't any other items near the water line. I looked very closely at the fiberglass shell to see if there were any fractures and could not find anything by looking and even feeling around the seats and stairs.
 
The dye test might still be an option, but the only problem may be that if the water has stopped dropping, there's no way to see where it is escaping from. :( One of those catch 22 things. You could add a little water just to see if you can use food dye and try to pinpoint the spot. If it's not the shell, then all I can assume is that the water pressure is strong enough to cause something underwater to allow a leak. Weird though. I am learning from your post/experience as well. I have the easy part though. :)
 
I'd do a very careful exam of the moulded area between the skimmer and return ( place to sit?) I'm thinking that you may have lost the supporting gravel( unless they used sand backfill) and that caused a crack in the moulded seats due to deflection.
 
Rkofamily- please be careful not to allow too much more to drain out as technically fiberglass pools should never be drained. Too much risk of having them pop out of the ground, especially if you're in a low lying area.

Have we ruled out a pipe leak instead of the shell itself??
 
I just conducted the dye test near the main drain and light. Nothing. The dye just floated along and did not pinpoint a leak. I did this twice. I also walked around the inside of the pool looking for a fracture especially at the seats and stairs. Nothing.

I'm putting about 2 inches of water in the pool now and will maybe try the dye test again at various places?

Still have not ruled out a pipe leak. My pump is still primed if they tells us anything.
 
Ok, I just checked Google for Starkville, MS and there are leak detection companies there. I think you better look to using their skills and equipment to find your leak.

I worry about your pool sitting empty much longer.
 

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