Indoor inground pool leak

[Harrisburg Pool Novice]

Is there a way to address what likely is a leak in the pool return lines without digging? Our pool is inground and indoors. Not only is there concrete around the pool, but also we installed carpeting. We've had a pool company try to locate the leak and have spent a good bit of money to find out that sonar won't work on top of the carpet and that to find the leak, they would "just have to start digging." We are losing around a half-inch or more a day, which doesn't sound like a lot until the end of the week when the pool is down multiple inches.
Has anyone had any luck with Fix-A-Leak, or come up with creative solutions to this type of leak?

[Toe In The Water]

No magic answers I'm afraid, but have you at least narrowed the problem down to an individual line? That may help minimise the impact of digging?

[Sharon]

Do you have solar heating on the pool. We had the same problem, pool leak guys couldn't find the source of the leak and then i noticed a trickling on the roof, one of the panels sprung a leak.

[Harrisburg Pool Novice]

Unfortunately, the sonar was to have helped to narrow down and find the leak, but we were told that it wouldn't work because of the indoor/outdoor carpeting. I would have agreed to digging up just one area and replacing that concrete and patching the carpet. I'm beginning to think that it would just be easiser to install new return lines.
I wish that we could say that we had solar panels, but alas that is not the case.
Thanks for the suggestions!

[Harrisburg Pool Novice]

Okay, so we put plugs in the jets (from the return lines) for about a week and we still lost a lot of water. We've had the entire leak tested twice and no leaks were found in the liner, around the light, steps, etc. (so we have now been told twice). Is there somewhere else that we need to check? The only thing that I have yet to do is to try to cover the bottom skimmers and see if that stops the leak. Frankly, I'm not sure how to go about doing that in the first place.
Common sense tells me that the leak, while slight since the pool was installed a little over two years ago, became more pronounced when the pool heater was replaced. However, the company that fixed the system assured us that it had nothing to do with that.
Suggestions would be appreciated pretty please.
So,is there ever a time when you actually just get to enjoy your pool?

[ChuckGeo]

I'd recommend water loss tests to help determine the location of the leak. Measure the loss from the pool over 24 hours, in inches, once with the pump on and once with the pump off. The same loss on & off indicates a leak in something other than plumbing. More loss with the pump on indicates a leak in the return or pressure cleaner line, while a loss that's more with the pump off is indicative of a suction line leak.
Is the pool heated? Is the room it's in dehumidified? High water temps and powerful dehumidification can pull a lot of water out of the pool. To test for evaporation, fill a 5 gal. bucket with water and place it on the top step of the pool. Wait 24 hours and measure the loss from the bucket - that will be your evaporation loss. If it's the same as the loss from the pool you don't have a leak!
If you end up with a plumbing leak, there is no choice but to lift the carpet to attempt to sonically locate the leak. At least if you have to dig it up and patch the concrete you can cover the patch with the carpet and pretend it never happened.

[Harrisburg Pool Novice]

The results of the tests:
1. We turned off the dehumidifier, to make sure that any water lost was strictly a pool issue.
2. We measured the water level and left the pump on -- we lost 1/2 inch over 24 hours
3. We measured the water level and turned the pump off -- we lost 1/2 inch over 24 hours.
4. We blocked one return line -- we lost 1/2 inch over 24 hours.
To date we:
1. Had the pool leak tested twice (same company, same results -- no leaks found).
2. Had the return lines pressure tested, company said it lost pressure rapidly.
3. Monitored the level of salt and have had to add salt regularly (we have a salt system), which company told us indicated there is a leak in the pool.
So, what else can we try? Taking up the carpet is not going to be easy, as the installer said he used glue that would ensure that it would not come no matter how much water, etc. hit it. As previously noted, the sonar wouldn't work through the carpet.
Any input is appreciated.

[Me...]

Since I didn't witness the pressure tests I can't be sure they were done correctly but .............. testing the water loss with the pump on and then off tells me that since they are equal it is most likely in the hydrostatic relief valve if you have one, a light niche if you have one, or even around the OUTSIDE of one of your pool fittings. You need to dye test all those places where a fitting or piece of equipment, including anchor positions for ladders and stairs, penetrates the structure. I have even seen 300 gallons a day leak out the screw holes of 6 floor inlets even with the screws in place. Another option is to simply let the pool drain and see where it stops.

[ChuckGeo]

I concur that it's not a return line leak. Based your measurements, I'd be dye testing around the wall fittings, light niche/conduit, and main drain sump/hydrostat. I would also look in the skimmer throat, where the skimmer butts up to the pool is often a trouble spot and in the skimmer body. Is the pool cracked anywhere?
To properly inspect and dye test return fittings, it's often necessary to remove the face plate and eyeball to be able to see properly and use a mirror to look under the fittings.
What is the pool size? I find it handy to calculate the gallons lost per day. For instance, a 20 X 40 pool loosing 1" per day is loosing 500 gal. per day. Here's the formula:
Inch loss, in decimal X pool surface area X .625 = Gallons lost.
Search slowly, don't stir up the water, get a dye test syringe from the pool store, apply the dye at any place that is cracked or gapped open, apply the dye wihin 1/4" of the suspicious spot - if it's leaking the dye will draw in, if not leaking it will accumulate where you put it.

Good luck. Let me know how it goes.

[Harrisburg Pool Novice]

Thank you for the posts. I truly appreciate your input. Not only was it valuable and wise advice, but it allowed me to believe in common sense again! Too bad neither 'Me" or "ChuckGeo" are in the Harrisburg area, or you would have another client!!
I will look for a dye kit. At this point, I am trying a different experiment: I put plastic wrap and bowls over the bottom drains to see if that slows or stops the water loss. It was a pretty funny adventure to watch, but if it helps to isolate the leak...
Because the pool is at least a foot low, I think we may leave it drain for a while to see if it stops somewhere.
I will go and buy a dye test kit, although I am concerned that at this point, the water is well below the scimmers and is now almost below the returns lines, so perhaps that will have to wait until we get a couple truck loads of water.
The pool is 18 by 36 (if I am recalling correctly).
I also am going to look into the screw issue, because the water has made all metal surfaces in the pool rust. It has only been in for two years, but with a salt water system, that could have been sufficient time.
Again: many, many thanks!

[LT1]

I also have a leak that the pool company used similar diagnostics. You stated in an above post that 'you had it pressure tested and it lost pressure rapidly'. Doesn't this mean that the leak is in the under ground return lines? Cant they throw various valves to isolate which section loses pressure? With the pump off, why not dye test any underwater return lines to see where it gets sucked in? Then I guess start digging?

[Andre]

Did you have any luck finding and fixing the leak in your pool?