Water leak for > 1 month: need advice

[tmarks66]

Hi folks,

When I opened my pool in May, I had no issues (that I could tell). It rained nearly everyday that month, and I remember scratching my head thinking that the pool level never met the built-in overflow runoff pipe. Oh well. After a few weeks now (and the backyard remaining swamp-ish even after the sun came out) - I can tell I have a leak somewhere. I knew I had issues in one corner where my vinyl liner has stretched and torn. I patched the heck out of that corner (using many smaller overlapping patches as that seemed to work better; used H66 vinyl cement), but the leak persisted. I was adding water each day to compensate. FYI, I am able to measure the volume of the leak by catching the output from an underground pressure relief drain pipe (the "spring" feeding my backyard swamp). Initially the leak rate was ~ 3oz every 30 seconds.

My latest step was to plug my skimmer pipe, and rule out (or rule in) a leak somewhere in that pipe. I plugged the hole at the skimmer, and set my valve to suck only from the main drains - so I can maintain circulation, but the skimmer pipe is out of the circuit. After ~ 2 days of this setup, the leak rate reduced to 1.5 oz/30 seconds. Aha. After 4 days, the leak is still there, but now even much smaller. Meanwhile, the pool level is down about an inch from nominal due to evaporation.

So, it seems like I have a leak in my skimmer pipe somewhere - would this forum agree?

I think there is also a possibility that I still have a leak in my vinyl somewhere between nominal water level and an inch below that.

My next step was going to be to fill the pool back up to nominal level, and see if my leak rate changes. If so, then I know I still have a problem with the vinyl somewhere.

If I have no leak once the water level is restored, I think I have solid evidence that the leak is in my skimmer pipe somewhere. If it is in the skimmer pipe, then I'm also looking for advice on fixing that. I have seen "Fix-a-Leak" on amazon. Fix-A-Leak says it "Permanently seals leaks and holes up to 1/8 inch in diameter in most any material including plumbing"

Has anyone used this? Pros/Cons? Other ideas?

Thanks for your collective expertise and advice!

 

[Texas Splash]

It does sound as though there's something going on in the suction line as the rate of water loss slowed dramatically once you closed it off. But it also sounded like you still had some water loss - much less, but still there. The repair technique depends much on the exact spot of the leak. While suction leaks tend to be a bit more forgiving since water is not "pushing out" as it does on the pressure (return) side, you still want the repair to last so you don't have to go back months later. Normally, if you have to dig down, you might as well replace the section that's bad anyways. That would be my take on it anyways. I've not used Fix-A-Leak on anything, so I can't knock it one way or the other. But for pool plumbing, and the fact that I want it repaired correctly and not have to go back a 2nd time, I probably wouldn't use it on anything buried.
Pool School - Leak Detection
Pool School - Suction Side Air Leaks

 

[tmarks66]

Thanks Pat,

An update here.. After plugging the skimmer suction line, the leak ultimately stopped completely - bone dry. Once I had that condition, I filled the pool back to nominal level to see if there was still any issue with leaks from the vinyl liner. That was two days ago, and still no leak. Last night we got some heavy rain and for the first time this year the pool water level reached the overflow drain. So now I'm fairly confident that my leak is in that skimmer suction line somewhere. I'm able to keep the water circulating by using just the main drains, and for now that seems to be working. I think I'll enjoy the summer in that mode, and sort out what to do with the suction line leak later in the season.