AG pool has a leak - close or fix now?

I have an 4 foot deep oval 15x30 above ground pool. I've had a slow leak all season. Not sure where the leak is coming from, as nothing is detectable. However, I believe it may be somewhere along the bottom of the liner. We had two incidents where refilling the pool water level resulted in accidentally allowing the level to rise over the top. Thinking that some washout of the sand base under the liner may have occurred. But I have also noticed that the face plate of the return has a hairline crack through where the screw secures it to the pool wall. So, that could be the potential source, too. Throughout the season, I never allowed the water to go down below the return to see if that might have been the source. At any rate, the lawn area around the outside of the corner of the pool where the lawn slopes downward has been extremely wet all season. So, the leak could be anywhere, but is finding its way to the place where the land slopes down. I estimate that I've been losing about an inch every couple of days throughout the season. I've just been refilling it. Well, now I am ready to close the pool. I've cleaned it and added the requisite chems, and I've inserted the winter plug on the return and placed the lid'l seal tupperware-like covering on the skimmer plate. And I've laid down the winter cover over the surface of the water for now. Haven't secured the cover yet.

NOW, WHAT CAN OR SHOULD I DO ABOUT THE LEAK?

What if I ignore the leak and secure the cover and just let it be? If the water level stops dropping just where that hairline crack at the return screw, then I've likely identified the leak and I can probably just leave it for now and deal with it in the spring. The water level will only be down about a foot from normal level, and the cover still fits properly.

What if I ignore the leak, secure the cover, and the actual source of the leak is much lower somewhere, like along the wall seam or along the liner bottom? What is the potential risk here, allowing the water level to leak out half way to a depth of only 2 feet or totally to the bottom of the liner? Obviously, the secured cover would need to be removed, because the weight of winter snow will collapse the pool wall. Is it ill-advised to allow the leak to continue throughout the fall and into the winter months, even if the cover is removed? How can that compromise the structural integrity of the pool wall? I should note here that my pool has a fantail deck at one end and a full wrap-around promenade deck that is about 15 inches wide, and the supports around the outer of the pool wall also fork out and help to support the promenade decking. Is such a structural design solid enough to withstand the winter if there is no water in the pool?

Should I somehow attempt to maintain the water level in the pool by refilling as needed throughout the fall and winter months? Obviously, I'm wasting $ on water, and ther is also the point where several inches at the surface will freeze, and I can't really raise the water level at that point. And what could be the ill effects of this scenario if lower water in the depths of the pool continues to leak and the upper layer of ice may lower with it?

Or do I need to get this leak identified and fixed right away before winter arrives?

Thank you.

The first thought that jumps into my mind is that if the leak is low, like toward the bottom of the liner, the liner will sit, dry, all winter, and likely will be destroyed by the first of next season. (Not to mention what it may do to the structure of your walls--I'll let someone with more experience with AG pools comment on that.) When a vinyl liner stays dry for extended periods of time, it loses its ability to stretch and when you refill the pool, will likely pull out of the track and not be able to be re-fastened. It may also dry out and crack...either way, you're looking at a new liner.

I think if it were my pool, I would drain enough water to get below where you think the problem may be in the skimmer, and just see if the leak stops. If so, you have your answer, and it probably can be dealt with next season. If it doesn't, you know it's below the return, and will need to deal with the leak before you close for the winter, otherwise you'll probably end up replacing the liner in the spring.

Janet