I've posted on geo-thermal before. Why is everyone sinking piping in their ponds? If you have a strong ground water source, just pump from your well through the geo units and dump to the pond. Ground water has a consistent temperture year round, and you save a bundle on all the piping and pumps needed for a close loop system. I hope no one fishes these ponds? One sharp hook in a pipe and all your anti-freeze goes into the pond. I'm sure the piping is tough to penitrate, but you have to careful. I'm been using a "pump and dump" set up for 5 years now in cold michigan, and my home is cool in the summer and toasty in the winter. I did have to spend more on an upgraded well, but the additional cost isn't nearly what these close loop installers charge, and open loop systems are way more efficient than close loop. Check out the manufacturers efficiency specs of the machinery with each style of loop. Open loop is much more efficient, an lower cost to install. The only catch is you need a realible source of ground water to pump. Just my thoughts.
