Leak detection and repair - suggestions?

[Spensar]

Before buying my house I had a pool service person check it out, which included pressuring the underground pipes only to check for leaks. He had a guage and ran a good test to verify if there were leaks there. That was several years ago and I can't recall the exact method, ie. did he plug the outlets, etc.

May be worth calling around and see if there is an experienced pro that can run such a test. I'm lucky to have access to a good one, that only does service and doesn't have a storefront so he isn't promoting "solutions" I don't need.

[waste]

Hi, welcome here!

Like Al, I'm sorry to have missed this til now

If the water loss is noticeably less with the pump off, it indicates a return side leak.

Is the entire area between the pool deck and the pump house concrete, or is there some yard involved?

Areas covered by crete can be checked (with ~ 50 - 50 chance of success) by using geophones (or Al's trick of a nail in a stethoscope) when running pressure through the line with the other end plugged to narrow down which section of concrete has to be ripped out.

Please keep us informed as to your situation (I promise, I won't miss it again )

[Poconos]

I think Ted is a little mistaken about the nail in the stethescope. He's got a good memory as that post was long ago. That trick was for listening for mechanical noises like subtle bad bearings. However the open end of the stethescope hose is good for finding air leaks if you can get to the leak. As for pressure testing the pipes, I do it every time I close for the winter and open in the spring. You blow the lines clear of water and cap the returns with plugs, then I can disconnect the plumbing at the filter and attach a jig with a tire valve and pressure gauge. Using a compressor I run up the pressure to around 15 psi and then see how long it takes to bleed down. The inline chlorinator will leak a little air but it still will take at least a day for the pressure to hit zero. Doesn't tell where the leak is however, just that there is one which you already are pretty sure of. I saw a water company guy use one of those things that Ted mentioned to find a water line leak. Pipe was about 5 feet down and he missed totally. The landlord had to dig up the whole 40 feet of pipe to find it. Sometimes they work but for small leaks I would think it's questionable. I don't know if there is such a device for finding water leaks based on electrical resistance to ground (at the leak) but I could imagine a device being based on a technique called time domain reflectometry that phone and cable people use to find opens or shorts in their cables.
Something tells me the best and cheapest option may be to simply dig.
Al

[George in Georgia]

Many thanks for the suggestions. I've been away since last Tuesday on a family matter, so the pool has just sat, no pumping. Water loss seems more than the evaporation from a measuring cup left out. Sunday afternoon I ran the pump sourced from the main drain (water level is below the skimmer) for two hours and saw no dectable drop in water level. This is encouraging!! It suggests that the returns are okay.

Today I'm adding water to enable using the skimmer; I'll try the two hour test again. Since the liner is in rotten shape I'd be "happy" to find that a replacement would solve the problem. I'll also continue the bucket test.

If the two hour test is successful I may still pop for a $250 visit from a leak detection company. BTW as far as I know the entire underground plumbing run is under concrete. Ratz!

Here is a link to the two products a Google search uncovered for a leak fixing additive: http://www.fixaleak.com/main.html and
http://www.lo-chlor.com/pool_chemicals/leak_sealer.php

Searching through old threads on leaks in this forum and another one uncovered one responder who'd used such a product in 2005; an email to him has produced no response. If you're out there please respond!

[George in Georgia]

An update. Since my last post I've run the pump/filter from the skimmer and from the main drain for 12 hours or more with NO discernably different drop from the bucket test. Loss since my last post is about 1/4 inch, easily accounted for by evaporation. The dogs seem to have drunk from the test bucket; it shows about an inch drop.

Talking to a dealer about a new liner he mentioned that a bit of trash could stop up a liner leak. Sounds reasonable. That could explain the sudden 3 - 4 inch drop, and its "miraculous" cure.

Someone on this or another forum mentioned that plumbing leaks accounted for only about 10% of all leaks. Since my plumbing seems to be all underneath concrete, with no indications of the slabs sinking, perhaps my situation falls into the 90% of leaks, the liner.

Any thoughts from The Collective Pool Brain???

[aylad]

As far as liner leaks go, I know that areas around light niches, steps, etc are common places for leaks. Otherwise, I don't really know what to tell you other than if you let the water just leak out, at least the water level will stop changing when you get to the level of the leak, and hopefully give you an idea of where to look.

Janet

[George in Georgia]

No drop in water level other than evaporative loss after about 18 hours of filtering. Looks like the plumbing is okay. After replacing the liner we should have swimming through most of September, here in the sunny south.

Many thanks for the group's suggestions and moral support through this and my prior green water adventure. When I get the new liner in I'll know how to start off right!