Update on my Leak

[b2001]

I discussed this in a previous thread, but most of the discussion has been about pool covers, so I am breaking this off into a separate thread. My situation:

My next problem is I recently noticed that my water level had gone significantly down since covered in October. There is about a foot of water in the shallow end of my pool. There has been very little rain this winter. We’re anticipating a lot of rain this weekend – I decided to remove the cover hurriedly last night to avoid a buildup of water on the cover, with the added weight that would cause the sides to collapse in absence to the support of water. I wasn’t able to do my usual thorough cleaning and removal of the leaves, and right now the edges of the cover are over the side of the pool at one end with the bottom of the cover too heavy to raise out because of the collection of debris that was on top of it and now in it. That’s another matter that I’ll figure out how to tackle. At least the rain is going into the pool and not collecting on top of the cover.

My issue is that obviously I have a leak. It seems to be going down about an inch every few days or so. At this point, the water level seems to keep going down – it seems likely that the leak is on the bottom of the pool somewhere. I had a incident with a lot of glass getting into the pool this summer, felt like I pretty much got all of it out. I didn’t seem to have an issue with the pool level going down excessively during the summer after this incident, but maybe that was not the case. The water is pretty dirty at this point. I’m not sure I have any choice but to let it continue to go down to see where it will stop. It seems like I won’t be able to do anything until I can get into the pool in the spring. The dirty-ness of the water would seem to impede locating a leak.

Any suggestions on how I can locate this leak? The liner seems to be in pretty good shape otherwise – although I realize there’s the possibility that I might have to replace it.

The water level was seemed to start at about 14" above the bottom at the shallow end when I first noticed an issue to about 8" or so when I got the cover off. I have a hard time believeing that all of this water loss is due to evaporation - this has never occurred over the winter before.

I did a lot of looking yesterday and did not see anything obvious yet. I'm not at the point of trying food coloring tests yet.

I added 2" inches of water yesterday from about 2 to 4 pm. There seems to be no water loss overnight - I checked it this morning at 8 am. It would seem if the leak is on the bottom I would have seen some loss overnight. I don't have a feel for evaporation loss at this point yet. My thoughts are to try to narrow down at what level the water is at - where the level is more stable - by adding a couple of inches every few days and observing loss.

At some point I'm going to do an inspection of the liner above the water level more closely, but I'll need a pair of rubber wader boots first!

[Poconos]

I'm a little confused about the type of pool. You mention a shallow end but imply the sides would be pulled in by weight of water on the cover. Doesn't matter for what I'm going to say though. Forget the food coloring, it could empty your wallet. A couple things I recommended in the past have been to get a dye marker at a dive shop and make your own dye. Another is to get some raw beets, dice them up and boil the heck out of them. makes a real concentrated, safe, red dye. Can eat the beets afterwards. I've developed a technique for finding small leaks using a small garden sprayer, a long piece of small diameter (1/2" or so) PVC pipe, and thin auto vacuum hose. Hose is taped to the pipe and jury rigged to the sprayer. Hose extends beyond the bottom of the pipe for 6" or so. Idea is to 'very slowly' position the hose with the pipe and squirt just a little dye in an area. Must have real still water and be within a few inches of the leak to see anything. I homed in on this technique searching for a leak at the deep end of my IG pool a few years ago. Also developed a method of laying a good patch without getting in the pool. If this stuff is helpful I can find the thread(s) where I posted in much more detail. Let me know.
Al
Edit: Saw in your other thread it's an AG pool so forget my question.

[b2001]

Also developed a method of laying a good patch without getting in the pool. If this stuff is helpful I can find the thread(s) where I posted in much more detail. Let me know.

Yes, if you can dig it up, it would be helpful. I have a feeling before it's done, I'm going to get good - at least at trying to find leaks. Of course, once I find the leak, assuming I'm able, the next question would be patching. Thanks ...

[Poconos]

Something else I forgot to mention. One way to get some rough idea of the depth of the leak is to measure the leak rate accurately. As the water level approaches the leak level the leak rate should slow. ex: in my situation with an 8' deep end, I topped off the water level and just let it go down about 1' below the skimmer as I recall. I was losing about 3" a day that calculated to be about 50 gallons per hour based on the surface area of the pool. Using a ruler and referencing a known spot like a point on the skimmer housing, I measured every hour or so and computed the rate. In my case the rate did not change indicating the leak was deep. In the limit the leak rate would go to zero at the leak level. I suspect if the leak had been at the 3.5' shallow end the pressure change with a 1' drop would have measureably slowed the leak. Something else I did to see what I should be looking for with the dye was to use a garden hose on the bottom of the pool and start a siphon at the same rate as the leak. Using the injected dye I then knew what I should see as far as the dye being sucked into a leak. I'll go dig up more info in the archives.
Al

Edit: Moving this thread to the 'pool construction and repair' forum. May get more exposure there as a better fit.
Edit: The pics for the leak patching are off the forum so I'll just have to dig them up and type the words. I'll get to that a little later today.

[Poconos]

Found the following thread:

http://www.poolforum.com/pf2/showthread.php?t=101

So.....look at my post #9 and see if you can see the 3 pics. This was posted almost 2 years ago so as an update, the patch is holding just fine. Last Summer I tried to peel up a corner and could not. Seems to be stuck real well. If you don't have double sided tape, which I didn't, just use masking tape folded on itself. The PVC pipe was 1.5" and provided the needed rigidity to be able to push on the patch. Hope this helps.
Al

[b2001]

I've been out of town for two days. As per Dennis' advice I added water to try to get the level to 2' but only got it to 19" before I had to go out of town. It's gone down 1 1/2" in two days so it seems that my leak might indeed be on the side in the 12" to 19" (from bottom) level. I'm going to see where it seems to settle at.

Thanks, Al - I'll look at your thread over the next couple of days ...