We moved into our new house in late September and closed the above ground pool in October. Pumped water level down below the return and covered it with a solid tarp like cover. A few weeks ago I checked the water level when I changed a seal around the return that was worn out and the level was essentially where we left it in October. 2 weeks later today the cover blew partially off in a storm and when I went out to fix it I found the pool water down another 18 inches or more from where it was a few weeks ago. My first thought was it magically sprung a leak? The only other thing I can think of is that we do partially pump the water that had accumulated on top of the pool cover off. Is it possible that there was water exchanging from the pool to on top of the cover and we were pumping water from the pool?!? If so how do we keep from doing that next time?
Also, the prior owners said they refilled the pool for summer using the well water. Is it going to be possible to still fill it from the well now since it is so low? Probably 18" below the return.