going to be startng a build on a new stingray pond 10' x 8' x 3-4' deep. The pond will be in the basement at a room temp around 20 degrees. My question is does anybody use underfloor heating currently on their ponds. If you do is it water lines or electrical? And do you think having a floor hot enough to maintain 28 degree water temp be to warm on the bottom for the rays?