I'm currently building a new home and am considering installing a Geothermal Heatpump with a pond loop. In my area my loop will be primarily used for heating. We are planning on digging a the pond to use as the heatsink for the loop. Can you give me any guidelines as far as how large the pond should be? House is approx. 2300 sq feet plus a basement at around 1000sq feet. What loop design is the most efficient/best for a pond. I've seen coiled, slinky, and even a hyperloop? My pond is going to be around 150 feet from my home. Does each loop need run that full length and back individually, or can there be a larger supply pipe that then breaks off into the individual loops at the pond, and then back into a larger return pipe back to the house? Are pond loops more troublesome then horizontal ground loops? Do you typically frame the loop with PVC pipe to maintain spacing once the loops is sunk? Would burying the loop with 6-8 inches of sand in the bottom of the pond increase, decrease, or have no impact on the efficiency of the system? Thanks in advance!