My first post! I also have geothermal heating and cooling, but instead of using ground loops, I use straight ground water in a "Pump and Dump" setup. My efficiency is way up from a ground loop because the inlet water is 52F in Michigan year round. I did have to get a large well pump to handle the load, but it was a lot less than the 20K the loop contractors wanted to put the loops at the bottom of the pond.
This setup has created a slightly different problem however. I dump the geothermal water to my one acre pond (15 ft deep). Pond is 4 years old and I've been fighting algae ever since. I added a windmill last year, but the aeration was inadequate. This year I added a gast pump (4-5cfm at 10 psi) with 4 membrane diffusers and run it 24/7. In addition I've been doing regular bacteria treatments I got from Stoney Creek (Whoa, this stuff is expensive!). The situation has improved, but I still get regular algae growth. Instead of killing it off with Cutrine, I've been physically removing it with a rake, and dumping it far from the pond.
The local pond guy said I have to much nutrients in the pond, but I don't know where it's coming from. No farm, no stream, the pond is groundwater fed, It gets rain and the occasional waterfowl. I just can't keep raking this stuff out! It's driving me crazy!
My only thought is the geothermal dump. I have 5 geo units so in the winter I dump on average 20 gallons a minute all winter long. This can easily get to million gallons over the period of a heating season. My raw well water has a moderate amount of organics in it. I has to get a tannin water unit to remove them for my drinking water. When I tested the water, there was 5 mg/liter of organics. No nitrites or nitrates but phosphorus was present.
To all you pond bosses out there, any clue as to what is happening? Thank you for any advice!
Eric
