Weird leak - how to deal with it / close with it. Hydrostatic Relieve Valve??

[ship of fools]

I will need to close my pool soon and have a major issue to either solve, work around or know what to expect in the spring. I have solved a couple of fairly major issues over the past few years with help from here and hoping for lightening to strike again

I have had an intermittent leak since last winter. Over the winter i lost about a foot of water. After dealing with a floating liner i had everything refilled and up and it was running fine for a couple of weeks with no leak. Over the next couple of months i dealt with it by adding water. In the meantime i patched a questionable spot on the steps as well as replaced cracked rings around the return. During this stretch of time it leaked whether the pump was running or not and there were times that the water level fell below the skimmer and i ran it on just the main drain and it still leaked.

Each time i would fill it back up it would leak again. I let it drop when i went to Florida for a week and it got to a certain spot and stopped. Towards the very end of the season i returned from Florida and filled it back full again and ran the pump while i cleaned the water back up and during that time it didn't leak. As soon as i shut the pump off it started to leak so i let it go again. It has stopped leaking exactly at the level of the top step in the shallow end so i have 6 or 8 inches of water in the shallow end.

It hasn't rained here to speak of in ages.

I had talked to one of the guys on here who is somewhat local to me and he helped me tremendously with advice on getting the floating liner back in place and i was left with only a couple of creases. During our discussions he mentioned it could be the hydrostatic relief valve. Apparently it can open and then not close properly - either work its way closed slowly or stick open.

So i really have two issues (3 actually with the dirty water and dead chipmunks but fortunately i how to get that fixed!)

One is the leak and the second is closing as it sits or as it sits after i fill it and it leaks again. I have another month or two.

As far as the leak goes it really doesn't make sense. I believe i can rule out the skimmer line since it dropped at the same rate below the skimmer as it did above. Since it stopped leaking is it safe to rule out the main drain or could groundwater make a pool retain that much water (up to the first step in the shallow end)? Logically the fact that it didn't fall to speak of when i ran the pump for ten days would point to a leak in the suction lines but it should stop when it drops below the skimmer or just continue to drop if it is the main line (I think?).

The leak seems like it is exactly at the top step. But it seems like if it was leaking there it would continue to leak even though the pump was running.

So any thoughts on the leak would be much appreciated.

First and foremost will a pool maintain water with it up to the top of the first step with a damaged main drain line or does the fact that it stopped rule out the main drain? Would that then point to the hydrostatic relief valve? If so how the heck do you fix those??

Now ... on to closing. My initial game plan is to fill it back up at least above the returns, clean up the leaves and the water itself and then close it and see what happens.

Is that amount of water in the shallow end enough to prevent problems? I suppose i know it isn't and at the very least risk a floating liner but i could face greater issues?? I am in upstate NY and we have relatively cold winters.

Any help / ideas would be greatly appreciated!!

 

[JohnT]

Generally hydrostatic relief valves are only found in gunite pools. Anything else in the pool at that same level?

 

[ship of fools]

Generally hydrostatic relief valves are only found in gunite pools. Anything else in the pool at that same level?

Yeah - i just read that somewhere. Since it is exactly at the top of the first step that would be the place to start looking ... or continue looking. I didn't see any rips, tears or anything.

Could it be the main valve malfunctioning and water escaping?

 

[custompoolcoversinc]

How old is your liner? I ran into a very similar situation this year with an old liner. It was actually tearing away from the bottom drain of the pool where it was almost impossible to see. It would lose 2-4 inches/week and got progressively worse throughout the summer. Leaks are tricky. You have to check inside of your skimmers, check your pool light conduit, etc. It could be anywhere.

 

[TreeFiter]

If the water level stops at some point, that indicates the level at which the water is leaking. It could be a crack in the steps, a hole in the liner at that level, or a break in the plumbing at that level. It could be leaking at one of the gaskets where the liner meets the steps. Where are your return jets relative to the water level (above?, below?).

Tracking down a leak can be tricky. Go around the liner at the level where the water stopped and carefully examine every inch around the pool. If you see anything that looks out of the ordinary, you want to test that spot. It might just be an odd looking seam, or a scratch on the surface of the liner. To test it, take a bottle of Phenol Red (the stuff you use to test pH) and squeeze out a few drops into the water at each spot. If water is leaking out, it will pull the phenol Red with it. It might be a tiny pinhole.

Check the plumbing at the pump pad. If you see wet spots around your equipment, that's usually an indicator of something leaking.

If you were losing water through a stuck hydrostatic valve, the pool would empty completely, or to the level of the water table. I'm doubtful that is the problem.

I would pressure test all of the lines to rule out a break underground somewhere. If you can get me some pictures of your plumbing, I might be able to talk you through how to pressure test your system.