I have a 5 ton Geo. Pond loop installed in 1/2 acre pond max depth about 9-10'. No significant changes in pond temp. compared to similar ponds nearby. Bottom diffuser aeration isn't significantly affecting efficiency but I don't aerate between November and February. Whole house electric bill last month was $100.43. Worst bill was this winter and a little over $300 but the thermostat was set at 74 degrees most of that month 24/7 and temps outside were often below 0. Going off memory, I think the pond loop install was around $1300, about a third the cost of a ground loop in 2003 but I don't think trenchless was available then. I looked at my loop this past winter with my Aquavu while ice fishing and it is still surpisingly clean and the blocks it's sitting on only appear to have sank about an inch. This might have something to do with aeration.
"The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge." Stephen W. Hawking
