This is a contraption made with a Top Fin air pump 4000 and some plastic pipe to keep an ice free hole open in the pond. The air pump is in a wooden box (with holes to let air in) with a five foot heater tape to keep the air going in to the pump warm. The box is covered with a plastic bucket to keep it dry. Two air lines are encased in a 3/4 in pipe which are inside a 3 in pipe and then insulating material covers the outer pipe. The air hoses go in to a 6 in pipe which is cemented in to an oil drain pan to hold it down. A number of holes are cut in the 6 in pipe to let gas out. One air hose extends outside of the 6 in pipe about 6 in below the water surface. The second hose is inside the 6 in pipe just below the water surface to keep ice from forming in the pipe. It seems to be doing a good job. This is the first time in 5 years that the pond will have an ice free hole