I have pumps lined out already and yes it is sitting on double high bricks. The bottom is 2x4 treated with insulation inbetween studs and then covered in plastic, bricks are spaced every two feet throughout. The whole thing will be 42" tall so there will be 12" of air space above the water. I am going to insulate the whole thing, have plc controlled heating of the water, and then control the air temp at the waters surface. In the summer the air will be pulled out allowing fresh to be sucked in and in the winter warm air will be forced in. I ran a pond the last two winters in the garage just covered with blue foam board but had it insulated and was able to keep 80 degree water with just 3 300 watt heaters. My garage is not climate controlled so it got down in the single digits a couple of times last winter