Playing 'find the leak'

[jreiser]

I'd love to treat this as a game, but thus-far locating the source of our pool leak has been anything but fun. We're renting a house with an in-ground vinyl pool about 30k gallons (105,000 square inches, average 5.5' depth) and just opened the pool about a week ago. The pool guy who opened it noted that the water level looked "a bit low" as compared with other pools he opened this season as we had a very wet winter.

The pool has two skimmers, three returns, and no main drain. The pump is located above water level, and there is a switch valve to control the skimmers (1, 2, or both). The multivalve is a bit old, but does not appear to be leaking out the waste line. (The waste goes out to the street, and there's no sign of water there unless we're backwashing or set to 'waste').

Now that we're open, the pool will not maintain a water level anywhere above the bottom of the skimmers. I ran the bucket test both with the pool running and turned off, and in both cases the water level drops dramatically from mid-skimmer to the bottom edge within 12 hours... losing about 600-1000 gallons.

Fortunately the water isn't finding its way into the basement, and so far we have seen no signs of where the heck it's going. The pool guy suggested the most likely cause would be a crack in one of the skimmer boxes.

Is there any way to test this to identify what's really going on? The only thing I can think of is to devise some method to block the skimmer closed and pour water in from above and watch how it drains. But I have no idea how to effectively block the skimmer to run such a test. I'd love to say, "there must be an easier way", but maybe that's why leak specialists get paid the big bucks.

Any assistance or commiseration would be appreciated!

- Jason

 

[RobbieH]

I paid $350 to have a leak specialist find my leak. They fully tested every aspect of my pool and it took them three trips to find the leak. In my case, it was worth every penny of what they charged me. I did watch them do the work, and they blocked off the skimmer and used a dye to run around the pool to find the leaks. The dye would shoot into the wall when they were by the leak. I had one in the skimmer (which I have been told is very common) and one near my diving board.

I'm not sure how they solve the problem in vinyl liner pools, in mine they used a kneadable epoxy that could be applied underwater.

 

[Bama Rambler]

You can plug the hole in the bottom of the skimmers one at a time and shut the valve off to that one and see if the leak continues. If it stops then the leak is in that line somewhere. If it doesn't stop the leak is in the pool somewhere, most likely one of the skimmer boxes. You can use food coloring to help find it like the they did on Robbie's pool.

 

[jreiser]

Thanks for the advice! Since the water level had already dropped below the skimmers and returns, I turned off the skimmer valves at the pad and tried filling the lines from the skimmer boxes from a garden hose. Sure enough - once filled, one of them holds water consistently, and one leaks at an impressive rate. There's no visible sign of where the lost water is going (lush grass for instance), but the leak is clearly in that line somewhere. So for now I've installed the winterizing plus in that one skimmer and began filling the pool again.

I'm off to the evil empire to pick up some bleach and see if I can get this pool in swimming condition over the next few days. With the one skimmer out of commission that might be a little tougher, but at least we can now look forward to a summer of swimming. I don't mind a little extra water maintenance, especially if we can avoid a water bill like the one last summer. Leaking a few thousand gallons a day gets expensive in a hurry.

Thanks again!
- Jason

 

[jreiser]

Sadly there's nothing trouble-free about our pool except the chemistry method I wish to use. Otherwise, it's a hole in the ground that swallows our hopes of swimming.

So I have a 3-way valve at the pad that controls the skimmers (A, Both, B). Since the "B" skimmer line leaks at a rate of thousands of gallons per day, I turned it to "A" (the near skimmer) and plugged the "B" skimmer with a winterizing plug. So the leak is basically gone (99% anyway) but now the pool just refuses to run well. We get almost zero flow, lots of air in the system, and it just won't keep a prime. Clearly it's taking in air somewhere but I haven't figured out where. This sucks. Literally.

One local leak specialist suggested that the 3-way valve (Haywood I think) may have a dried out seat gasket. When that happens the valve may suck in air from the atmosphere or maybe the faulty "B" skimmer line that's now filled with air. Everyone says he's the leak guy to deal with, but naturally he's booked solid for weeks. I asked my pool guy to replace the seat gasket in the 3-way valve since it's a cheap part and probably not *too* much labor, or even replace the whole valve if he'd prefer, but now he's ducking my calls. I think I must have hurt his ego or something, or I've just discovered that this is a sideline and his full-time job is coming first.

Does a bad seat gasket (or gaskets?) sound plausible? I'm handy enough to attempt this myself, but being a rental property that complicates things just a tad. If only the owner were responsible and gave a darn...

There's nothing worse than staring at a green pool in this weather, especially when I've got the test kit, bleach, borax, and everything else I need to get the water sparkling on hand. I just don't have a working pool.

Thanks,
Jason

 

[jreiser]

Replying to myself in case anyone is following this...

So today I topped by the local pool supply store and they suggested replacing the o-ring gasket on the pump. Another store had it in stock, so being a pretty simple DIY job and an inexpensive part, I gave it a shot. Naturally when I came home from work with the gasket and lubricant in hand, the pool water was completely still. It turns out the pump had pretty much run dry or developed an air lock. I'm not sure of the right nomenclature, but the clear output tube from the pump had water on the lower half and air on the top half, and it wasn't moving anywhere despite the pump running and the pool water level being high enough. I shut it down quickly and discovered that a pump generates a LOT of heat! Enough in fact to literally boil the water in the pump! I'm glad I thought twice about touching anything before allowing it to cool down.

Anyway... I replaced the gasket, primed the pump and gave it a whirl. For about three minutes it looked great, but then no dice. Once again it sucked in air from somewhere and caused the circulation to come nearly to a halt.

I swear, if it were a gunite pool, I'd have drained it and grabbed my skateboard out of storage. I may be nearly 40, but Tony Hawk's a few years older. My wife's happy this was never an option as I'd probably have broken my neck. And then she'd have to explain the empty pool in need of marble dust to our landlords. But I digress...

So... where to from here? Two pool stores say it's probably the housing gasket or other gasket(s) inside the pump. It's basically a Hayward Super II but sold as a Leslie Pools house brand. A leak specialist who is unavailable and my pool guy who may have time this weekend both suspect the 3-way valve that controls the skimmers. Everyone so far seems to agree that it's likely NOT the multiport valve as that's on the out-flow side and sucking air would generally be before the pump. I may open the valve and see if I can lubricate the gaskets or o-rings in there.

Thanks!

 

[Bama Rambler]

Have you tried running water over the 3-way valve while the pump is running to see if the air stops coming in. You could possibly narrow it down by doing that. The 3-way valve is a possibility as one side is seeing air through the leaking skimmer line.