Another year another leak

[Patrick181]

Mysterious leak

Hi, Gunite 20x40 salt pool My pool failed the bucket test. Long story short, I drained the pool to just below the skimmer inlets and shut off all three suction valves (two skimmers and one drain). One skimmer holds water, the other does not. I poured water into the skimmer that doesn't hold...

www.troublefreepool.com

Last year I had a leak in a skimmer line at an elbow, this year there's another leak in the same area but on the return costing me an inch a day. Both hairline cracked under the elbows in the same place. I have the pool opened and closed professionally but this year, I found a compression plug in the bottom of the pool after the team left to open for the season. Interestingly, that plug had fallen out once before but I caught it in time. I can also tell that one of my gizmos has some chewed up threads. I cannot tell if these lines are freezing in this area or if there is another element at play. I don't plan on engaging the pool company for this as I cannot fairly tell if these freezing up or not. I can say that the level of difficulty finding someone to fix underground leaks is extraordinarily difficult in my area so I'm going to fix this myself again. (you can judge my handywork of blue PVC cement on that skimmer line in the photo but hey, it doesn't leak.)

Two questions:

1. What is a good way of making sure water is not filling these pipes over winter?
   1. Typically I pump the pool down below the returns of rain water (mesh covered) October through February then take advantage of the free rain fill-up after January/February-ish though we still experience freezes then. Do you have a strategy for this?
2. Would it be a good idea or not to install a valve box over this bundle of lines for easy access? Because the digging up of this soil is the hardest part of these repairs and would be handy to open a lid to inspect for leaks there.
   1. Understanding that if a leak occurs again in this area, I will likely need to dig up the box but thats still a few cubes of Missouri clay I dont have to dig out. I just worry about exposing the lines to air over the winter. Perhaps I can stuff insulation in it.

Thank you,

Patrick

 

[PoolGate]

Can't you just make sure they are filled with anti-freeze? Usually lines are air-locked with anti-freeze but I suppose you could fill them all the way. Also how cold does it get where you are to freeze solid 2 feet below ground?

 

[Patrick181]

Can't you just make sure they are filled with anti-freeze? Usually lines are air-locked with anti-freeze but I suppose you could fill them all the way. Also how cold does it get where you are to freeze solid 2 feet below ground?

When they come out to close the pool, I see them adding antifreeze into the returns but I don't know how much. In my area, in winter we don't see sub 20°f much but it bottomed out at -6°f for a day. Everything I wrote about the root-cause is speculation. They could have dropped the plug when they opened and forgot about it. It's just odd (to me) to have a similar break issue twice in concurrence with an opening. It's also plausible that those 30 yr old fittings have had enough of shifting ground.