After I got out of the hot tub at 8:30 the one night, I noticed the water level was a little low. Since the hot tub is on the patio, it's easy to refill right from the outside hose. So I dutifully trotted over to the hose, dragged it to the hot tub, and started topping it up. It takes a long time for the hot tub to fill, so I left it running and …