Leak! Ug. Any advice?

[contento]

Greetings all. I woke up a week or so ago to find my concrete inground pool a good 10" lower than the night before. The pump was running over night but there were no wet spots anywhere (plumbing, grass, etc). It was down to just below the skimmer. There are no visible cracks anywhere. It was suggested that I let the pool continue to drop and see where it stops which would indicate if it were leaking around a fitting (return port, light, vaccuum port, etc). Well, it has progressed steadily below both returns and below the dedicated vaccuum cleaner port and is approaching the light fixture. I tried using my Ph test dye to see if I could see the dye tracking to the leak...not so much.

So, any suggestions are appreciated!
Thanks!

 

[bk406]

Do you have a main drain in the bottom? If so, is there a way to shut it off?

Since its concrete, i wouldnt think the shell would have sprung a leak that big that quick. If it's not a main drain, it could be the light niche. Are you sure you discounted any leak around the equipment? Do you have a filter you can backwash? Maybe the spider gasket went bad in the multiport valve and is leaking water out the backwash hose.

Can you give us a better idea of your equipment?

 

[contento]

The pool has 1 main drain, 1 skimmer, 2 returns, and a dedicated vaccuum port that a Great White auto cleaner runs on pretty much all the time. The valves are all plastic ball valves (I know, not the best choice...tell that to the installer). I have closed the main drain valve as best I can, which should be shut fully. It usually does. There are definitely no leaks around the equipment, and its been leaking for days still with nothing running.

If the main drain line were leaking betweem the pool and the pump, wouldn't it continue to leak regardless if the valve were open or shut? If the valve is shut and still leaking after it clears the light fixture, is it safe then to assume it's the main drain line between the pool and pump (barring any structural leak)? At that point, my options would be dig up the paver patio and BBQ slab to find/repair, or plug the main drain, right? Seems like an easy choice assuming I'm not screwing the pool up by doing that.

Thanks for the quick reply!

 

[lightingguy]

If you're lucky a winterizing plug into the main drain line might stop the leak. If it doesn't stop at least you've ruled out the main drain plumbing.

My pool has had a plugged main drain for years now. It's not great for circulation but it doesn't make the pool unmanageable.

 

[contento]

Wonder if the pool stores here even have winterizing plugs. Not much winter in south Florida! Worth a shot.