Indoor in-ground pool leaking

[qwazi]

I've only owned this house 4 years. My pool was originally outdoors. It is between 20 and 30 years old. Our house was built around it and it became "indoor" except the area isn't heated, it's just enclosed. It is a vinyl lined pool and it appears there is a single main drain, a skimmer, and 3 outlets. There is a 1 speed motor, cartridge style filter, and a old heater that is simply either on or off. No thermostat. I estimate the pool is about 20,000 gallons. The equipment room has a crawl space hole in the floor to access some of the plumbing that runs the long side of the rectangular pool.
Several weeks ago I noticed the level was getting low so I added water. I forgot about it so it overflowed. (Not the first time I've done that). Afterwards the water level began to drop drastically. Like a foot in a day. I had a line leak once but that patch was still holding. I figured I would let it drain until it got below the leak. In hindsight maybe not a good idea. It has now lost more than 3/4 of the water. I have no idea where it all goes except into the ground. We live very close to the Great Salt Lake and our water table is very high. This leak could be pluming and not the liner but I don't see any water in the crawl space. The liner was poorly installed. I think it's too small. The stairs have a bunch that has pulled away like it needs stretched to fit correctly.
Where could this leak be? Any ideas how to search for it with the little remaining water?

 

[mknauss]

You know the leak is at or below the current level of the water. Likely the main drain as far as it has fallen.

Let's see if we can get some others to provide some ideas.

 

[Newdude]

Got any pics of the stairs ? It sounds like the liner floated there, either due to the high water table, or the leak. Add some shots of the pool and equipment too, when you have a minute.

 

[ajw22]

We can all guess but the thing to do is squirt food dye in various places around the pool and see where it flows. With a leak like you describe it should become obvious when you hit the right spot. Anywhere in the floor of your liner could have split.

If you see anything you can gently squirt a little food coloring in the area and see if it gets drawn into the place you think may be the leak ‘ the water should be calm, don’t stir up the water while squirting, you are looking to see a tendril of the color being drawn into the leak

Dye Testers and Dye

Check out the deals in Dye Testers and Dye at Anderson Manufacturing Company, Inc.

www.leaktools.com

Leak finding alternative to food coloring

I can't find the old style food coloring in my area, it's the gel kind. I'm going to pick up laundry style dye. If anybody know this will work or will not let me know, or if there is any other types I can use. Thanks

www.troublefreepool.com

 

[qwazi]

Thanks for the replies. The liner has really wrinkled severly since the water has gone down. I'll get pics of everything posted here in a bit.

 

[qwazi]

Pics

 

[Newdude]

Great job !!! Hopefully they stir some thoughts. Allen posted some great reading in the meantime above.