Indoor pool leak

[kokot]

I have an older indoor pool that's been leaking for a while now. At first I thought it was evaporation. It started to leak more back on Feb/March - it'd lose about 0.75" every 24h. At the same time I noticed air in the pump that would not go away. I'd turn the pump off and in a matter of a few months it lost most of the water. So I drained it to about 2 feet of water and it continues to leak. In my view, the only possible leak sources would be the three floor outlets with returns and drains. There are there total - two in the deepest section and one on the opposite side. I have removed and reinstalled the rubber plugs on all three and filled it with about 1ft of water to cover the bottom - it still continues to leak. I've tried pouring water with die around the outlets yet I can't see any water movement indicative of a leak. Is is possible that it's leaking though the concrete, even though there are no visible cracks? Would the pressure test be the next logical step? Thanks.

- - - Updated - - -

I was trying to attached are a few pics of the outlets but the system doesn't let me.

 

[cowboycasey]

Your at the limit for posting pictures through TFP unless you want to donate..

Did it stop leaking at a certain level? when it stops that is where the leak is, well just above it

 

[kokot]

I didn't wait until the leak drained it completely, but it kept leaking past the skimmers. The only obvious (to me) potential leak sources are in the floor of the pool that includes the three floor suction outlets and what it appears to be a hydrostatic pressure valve.

 

[duraleigh]

That is enough water loss to confirm the leak. especially since it's indoors. The problem is then, "Where is it?"

Can you let it leak on down until it stops? (that'll be the level of the leak and you should be able to find it from that.)

 

[kokot]

This doesn't make sense to me but it's now been two days and the level of water hasn't dropped and it coincides with the two consecutive warm days this season (75-80F) after several weeks of wet and unseasonably cold weather. As a background, since I've had the pool I noticed that during the winter months I'd be losing significant amounts of water then it would stop when the weather got warmer it would stop. I'd add water and be OK for the most part during the warm months here in PA. In the the early month of this year it looked like I was losing more water than previously though, which prompted my investigation. Now. I'm confused as the leak seems to have stopped. What would be a correlation between indoor pool leak and outside temperatures? My house sits on a sloping hill if that makes any difference.

 

[kokot]

I'm back with the same problem. It took almost a year for the leak issue to reoccur.
Out of the blue, ever since the Easter we've started to lose water at the pace of abo 0.75-1" every day.
The pump had been going and the heat was on as they weather got warmed and we were looking to get back into the pool.
I turned the pump off about three weeks ago and water continues to leak somewhere.
Other than plumbing, what are the chances that water is escaping though a crack in the the concrete and is there any way to detect it? There's only one pronounced crack going through the steps but I believe water continues to leak past that crack. The last time around the water kept leaking all the way down to the return valves in the floor. Right now it's about the pool light level, past the skimmers and it continues to leak.
I may have to run pool pressure test to determine if it's the plumbing.
Any ideas are greatly appreciated.

 

[pooldv]

Leaks can be tough to track down. Here is an article from pool school with some tips, Pool School - Leak Detection

 

[kokot]

I followed the lead from Pool School - Leak Detection which btw is a helpful article.
I did a test with a food coloring around the return wells and I think I may have found the leak. With the pool half full the test was inconclusive however when after the water was almost gone it was easier to see the tendrils of the color pulled drawn into the rubber plugs in the drain outlets. I have just replaced them so the material is new. What i noticed though is that the drain outlets should have been closed off with threaded plugs with orings instead of the rubber ones. Am I correct or one can use the rubber plugs in threaded outlets? I'm going to try to source them locally this week and replace the rubber ones and test it again.
Also, there's an old unused return (non-threaded) plugged with a rubber plug (8) which also may be leaking. Do I need to get a better quality plugs or can they be sealed with silicone lube or other material?

 

[zea3]

I think you get a better seal with a threaded plug, but you can use the rubber ones in a threaded outlet. I would get a new rubber plug for the old unused return.

 

[kokot]

So, I'm back after enjoying three years of trouble free pool. Don't mean to resurrect an old thread. Feel free to move it as appropriate.
This time around it's only leaking while the pump is running. Had it sitting for 48h w/pump off and the water level is unchanged.
Where do I start?

 

[zea3]

Do you see water around the pump, then check the mechanical seal first.

 

[kokot]

Not much water around the pump, other than occasional superficial water around it. Is the mechanical seal inside of the pump?

 

[zea3]

The mechanical seal is between the impeller and the motor and prevents water from reaching the electrical parts of the pump. If the area around the motor is always wet when the pump is on the seal is probably bad.

 

[kokot]

I'm going to run the pump today and take note of any water around it.
But even if the mechanical seal was broken, causing the leak wouldn't the water leak above ground/concrete? We've lost hundreds of gallons so far, which it would have been noticeable in the pump room if that were the case, no?

 

[zea3]

You didn't say how much water you were losing. A bad mechanical seal would be a minor leak. Do you have a main drain? Do you have more than one skimmer?

 

[kokot]

Well, I can rule out the pump as the culprit. I’ve lost about 5 inches of water in the span of 1.5 weeks. Another detail I neglected to mention I’ve been installed running solar heat panels. I’ve just noticed a leak in one of them. Will have to investigate it further.
I do have two skimmers.

 

[kokot]

Since I had never addressed the problem last year (due to many reasons) I'd like to give it another shot.
I did some measurements for a week in March and the water level drops about 0.25" every 24h when running the pump internally (no solar panels) . Pool size is 15K gal. Area around the pump stays relatively dry so the water is escaping somewhere in ground.
When the pump isn't running water level stays unchanged.
The original leak from 2017 had to do with cracks in concrete around the returns in the pool floor. Once fixed with the compound it was good until last year.
I suspect the leak is in the pipes between pool and the pump. I think they're PVC (black).
Again, any advices from the tfp experts are appreciated.

 

[cowboycasey]

This is the only one I know of without digging everything up and replacing

PipeFuze

PipeFuze is a polymer based pipe injection system designed to repair plumbing lines without the hassle of cutting through concrete or digging up the line.

www.pipefuze.com

 

[kokot]

PipeFuze sounds a bit like snake oil to me. I'm yet to find a successful real life application of it.
I'm more inclined to hire leak detection pro for 500+ if I don't figure it out this week. One company told me they require clean, functional pool with at min 80F water. I guess they dive to inspect it.

 

[kokot]

Given water level is now below skimmers and there are two suction ports (in the pool floor) and two supply jets (by the skimmers) would it that eliminate the skimmers as potential root cause?
If I were to isolate the circuits and pressure test the plumbing I guess the supply ports need to be broken off as they don't seem to be designed to be removed for service.
Also, after the pump is turned off, it looks like water is running somewhere for a while. Perhaps it's gravity that's forcing it back to pool. Here's a clip.