Thought I'd share this weird tale: Last week we got hit with a record-breaking downpour. Our pool has a Coverstar cover, which was closed when the rain hit in the middle of the night, and we didn't have a chance to set out the pump. When I finally got to the pool I had never seen so much water on the cover! It was nearly to the top of the bullnose. After pumping off the cover and rolling the cover open, the pool was down about 6 inches. I freaked because at first I thought we had a massive leak but no. Apparently what happened is that the weight of so much water on the cover forced out some of the pool water underneath. I'm guessing it went into the trough that the cover rolls into, and out the drain. We've had this cover for seven years and never experienced anything like this, so it was pretty surprising to me that so much water could be squeezed out of the pool... but there is no other explanation that comes to mind. FYI.