Our inground pool has been closed down for the winter. We decided we needed to lower the water level in our pool as the water was above the vinyl liner coping and water was getting behind the liner causing liner float. We turned on the pump and pumped out water to below the skimmers. We turned the pump back off so it would not run. The next morning (approx. 12 hrs later) when we woke up the water level in the pool had drained drastically! As an experiment, we filled the pool back up to just below the skimmers and by the next morning the water level drained drastically again. Does anyone have any idea what could be happening? The pool held water all winter long until we turned on the pump to drain the pool down some. I would appreciate any ideas. If I can clarify any details please ask. Thank you for reading my plea for help.