Well I'm not sure there is anything that can be done at this point, but I discovered that I had a leak a few days before a big freeze was setting in here in Nashville. My choice were keep filling it up so I could run the pump or try and lower/close. I opted to close it up and the water kept draining to about 2-3 inches in the shallow end (I have an inground gretian with an 8' deep end). Things seem to have stopped. Anything I should be concerned with at this point? Having it that low in the shallow has me a little nervous.