My Pool is Leaking

[hallidina]

Hey, new to this forum, but loving it.
Moved into a home late last year that had an existing 18 x 36 IG pool.
This spring, we had to replace the liner, which we did using a local pool company.
The water level continues to drop (by 1/2" every night) - but only when my equipment is running - when it's not running, water level is stable, decreasing only slightly (I'm yet to do the bucket test).
I've had a pressure test done and the pressure is holding. I have a few minor drips from my pump and sand filter.
Any ideas?

Have never had a pool before, and presently am regretting it!

I'm just outside Toronto (Canada). The pool was partially "winterized" last year - it was not covered - because the liner was already shot - but the pool company did blow out the lines etc and winterize my equipemtn.

 

[Richard320]

Welcome!

Others have reported the same symptoms. I think the last one turned out to be a bad multiport valve gasket causing it to always leak to the waste port which was hard plumbed to some distant discharge point out of view. But this is all speculation, as we have no idea what sort of equipment you have.

 

[hallidina]

Hey, thanks for the quick response!
This is what I know: ~26,000 gallons, IG vinyl, sand filter.
The pump is a "Magnum 1000" and the filter is a sand filter "Jacuzzi Laser 250".
What else do you need?

What is a multiport valve gasket? And if that is the problem, shouldn't I see some water on my equipment pad? It's moist from the drops coming out of the Magnum and a little around the filter, but not 1/2" a night moist!

 

[Richard320]

When you backwash, where does the water go? That's where you need to look for leaks.

The multiport valve is that thing on top with filter/waste/recirc/rinse etc on it. The gasket is inside it. First look for leakage. Worry about what the gasket is later.

 

[hallidina]

There's only a bit of moisture around the equipment not nearly enough to account for what I'm losing from the pool...

 

[hallidina]

Anyone else have any ideas? Appreciate the help!

 

[zea3]

Some pictures of your pool and equipment will help us trouble shoot the problem. Do you keep the backwash hose on the filter or is the backwash line hard plumbed?

 

[hallidina]

I've not had to backwash yet, but believe the hose is on the filter (not hard plumbed). I will send some pics in the evening when home. Thanks.

 

[hallidina]

Some pictures of pool and equipment as requested.
You'll see, on the 2nd picture with the skimmer, that I placed some tape to see how much water I was losing. In about 12 hours, the water level dropped from the bottom of the black electrical tape, to where it is currently - this is with filter on. Water loss when filter is off is negligible I think.

Aside, not sure this is at all related to the leak or if it's another issue, but a fair amount of sand in the Polaris bag today when I emptied (maybe a handful of sand).

 

[hallidina]

Any ideas?
I've called a leak detection company and they can have a look, but looking alone is $400

 

[zea3]

Do you have a main drain in the floor of the pool? I can't tell by looking at the picture?

 

[hallidina]

Hey, there was a main drain in the deep end, but it was filled in w/ concrete when the liner was changed.

 

[zea3]

Is it covered by the liner?

 

[Bama Rambler]

If it's only leaking with the pump running then the shell is fine.

Also, it pretty much has to be on the discharge side of the pump.
Do you see any wet spots along the route of the plumbing from the pad to the pool?

 

[zea3]

That's where my thoughts are going too. You may have a problem somewhere in the return line. The ground might be softer in the area of the leak or the grass may grow a little better in the general area. If the problem is under the decking it will require busting up some concrete to fix.

 

[hallidina]

The main drain (which has since been filled) is covered by the liner.
I don't see any wet spots between pool and equipment pad. It could be under the concrete surrounding the pool possibly.
I'm going to do a bucket test w/ the equipment off to confirm that I'm only leaking when equipment is off.

Could the leak in one of the lines be so insignificant that the pressure test wouldn't pick it up - but big enough that when equipment is running, I lose as much water as I am?

PAINFUL.

 

[Bama Rambler]

Losing as much water as you're losing you'll pretty much fail a pressure test. It might be pretty easy to run a pressure test on your pool. How many returns do you have?

 

[hallidina]

That's the problem. My pool company did run a pressure test and the pressure held at 10 psi. I have 3 returns + one dedicated for Polaris + one for auto fill.
He tested them all, and redid the plumbing so that the water slide is no longer connected (as he couldn't pressure test that line)....

 

[Bama Rambler]

If they did the pressure test properly then the water has to be going somewhere else.
Do you remember what pressure they used for the test?
And how did they pressurize it?

 

[hallidina]

I don't know how they pressurized it, but he should me a meter showing pressure holding at 10 psi.