So, towards the end of last pool season, 2015, I began noticing the water level start to slowly drop. Nothing too extreme but enough to be noticeable and enough to make me worry. Eventually, I figured out that it was dropping only when the pool pump was running. This could only mean one thing, there was a leak somewhere in the "return" plumbing - a hose leak or more likely a fitting had come unsealed.
Thinking of how bad this could be kept me up at night worrying. Wondering if I'd need to begin cutting the concrete decking in and around major areas like the skimmer boxes or each of the three returns, UGH!
I chose to delay worrying about, or looking into this any further, once the pool was closed for the season. However, as opening day approached so did my anxiousness.
Well, as luck would have it the leak presented itself to me! It did so shortly after starting the pump for the first time this season, and did so in the only area that didn't have concrete over top of it, BOO-YEAH!
There's not much space to work in, add the tubing running down and it's more challenging. However, about 12 - 15" down I found the problem - a PVC T-connector had come unglued from it's tubing. We were able to dig down enough to expose all pieces, dry and clean them good and re-apply a generous amount of PVC cement to correct the problem, HOORAY!
The pool now looks like above and has already had a bunch of use!
We got SUPER lucky with this repair.