Losing Water

[affordlux]

My son just bought a house with a vinyl liner inground pool and the pool is leaking water to the tune of about 3 inches overnight with the filter off. He let it go until it stopped and it stopped just below the skimmer face plate. Aha, must be the skimmer gasket I thought! Filled the pool to mid skimmer level and squirted the food die all around the skimmer face plate. No dye got sucked in. OK must be in the liner along the level of water just below the skimmer face plate. Went around the entire pool squirting food dye all along the water level and just below. Nothing go sucked in. The water is above all the return lines so I don't think its a plumbing problem in the return lines. We squirted dye around the light fixture which is also below the water level and it also looked OK. I am building a pressure testing stick tonight to check the skimmer plumbing lines to see if it holds pressure. I'll let you know how that goes.


My problem is that on my pool filter I have a handle that shuts the main drain or the skimmer or if I keep the handle centered it feeds water from both the main drain and the skimmer. His pool is older and has large outdoor type faucet handles that have no markings so I am not sure what they do. I have attached a pic. I also have two separate lines for main drain and skimmer. I have read in these forums where sometimes BOTH the main drain and skimmer lines meet at the skimmer with only one 1 1/2" line going back to the filter. How do I know which design he has? I can screw the pressure testing stick into the skimmer but if I cannot close the skimmer at the filter I can't pressure test it, right?

The ironic thing is that this son helped me run two new return lines that were leaking in MY POOL just a month ago! Well, if we have to replace his skimmer line at least he will have some experience!

I could not get the picture to upload. Any advice you can provide to help me find this leak would be greatly appreciated.

 

[affordlux]

Here is the pic I couldn't upload earlier.

 

[needsajet]

Nice to meet you via TFP!

Here's the link for picture handling: Posting Photo's Tutorial
A picture will make it easier.

Otherwise, everything you've mentioned sounds like suction side, so just focus on that for now. With the pool full, maybe try your dye test inside the skimmer with any guts removed.

As far as valves, while it's running turn them partly or nearly closed, and you'll hear the water noise (increased turbulence) as flow is restricted. You can also look/feel where the flow slows down at the pool end.

- - - Updated - - -

OK, I see you got the pic loaded. Excellent

With the pump running, close each one in turn and see what changes at the pool end. One is probably the main drain. Do you have 2 skimmers?

 

[affordlux]

There is only one skimmer. All of those faucet handles shown in the picture do NOTHING! Only one of them (the one on the far left) has a start and stop position. The other two can be turned and turned either way and they never stop turning and have no affect on the flow of water in the pool or to the filter. We found some literature on the pool and discovered it was built in 1987. Unlike my pool, this pool has no bottom drain in the deep end. It has a side wall skimmer and then opposite the skimmer, a wall mounted line that has a cross grill that is another suction point. This port is about at the same height as the returns. I have never seen this type of setup and would welcome some insight.

Today we tried pressure testing the skimmer. We placed the filter on closed and I screwed in my pressure stick into the skimmer line and hooked up a hose to the pressure stick. We turned on the hose and the pressure would not register on the pressure gauge. We noticed that the hose water was entering the pool from the other suction point the sidewall "drain". We plugged the sidewall drain and tried again. The gauge was showing pressure but losing pressure. We saw water coming out of the pre-filter basket which accounted for the line not "holding" pressure. Does this test prove that the skimmer basket and sidewall drain are on the same line? Does putting the filter on closed make any sense?

We decided to go back to the basics. We filled the pool and marked the water level. Then we closed the skimmer, the side-wall drain , the returns and the robot lines. If the pool loses its customary two inches of water overnight, we will know we have a liner leak and call the liner fix-it guy. If the water holds, then I think we have a plumbing line leak. Without a way to shut off the skimmer line at the filter, I don't know how to pressure test that line without cutting it at the filter. Since none of the faucet handles work, I cannot even identify which line is which. HELP!

I'll post the results of the water level tomorrow.

 

[affordlux]

OK. After plugging all lines the pool lost 2.5 inches overnight. Called the liner patch guy. Coming Thursday morning.