Ok- I get the idea now- thanks for clarifying the "coil" thermal transfer idea. Seems like I would need a high thermal transfer pipe material like copper and lots of length of piping to get enough transfer to make it work. PVC would insulate too much to work. I like the idea- could take some engineering to make it work right. Thanks for the ideas! I thought that the ultimate pond cooling / warming would be to actually trench a geothermal line (6ft. under) and about 700 ft loop and actually pump pond water slowly through the line and then back into the pond. In summer you get cooling to 50 degrees (in Michigan) and warming up to 50 in winter. Of course, you're going to pay probably $10,000 for all that deep trenching and pipe laying adn pump etc., but it is an interesting idea.
CECIL:
Any guy who can get monster browns from a 1/10 acre pond is the Trout Master! Re: unplugging and plugging in the aerator vs a thermostat- you gotta check this Ranco $75 thermostat out- it works wonderfully! I've been using it since June. It has a 6ft. lead wire and sensor on the end.
My interim solution wa to put a 220 volt capable mechanical timer on the aerator- for night - time aeration and cooling. BUT, problem being, I live two hours away and even if you are on-site, who has the time to constantly monitor and guess how hot it might stay at midnight on those blistering summer nights, where you don't want it on and would have to manually unplug it etc.
So- with the night-time only aeration technique, I could still be warming my pond up 1-2 degrees in one night IF the temp stayed up at 85 and my pond was at 65 (a 20 degree difference from water temp!) and churning the convection oven- OUCH! By installing a RANCO thermostat, see ACF greenhouse supply link listed in previous posting above, then I can adjust the upper threshold of turn ON of aeration just a few times during the summer season.
Here's the basic setings I worked with:
Water temp = 60 / aeration ON at 58 or lower
Water temp = 65 / aeration ON at 63 / Off at 65
Water Temp = 70 / aeration ON at 65 / Off at 68
For Fall / Winter my new strategy is:
Water temp is currently 44!
ON at 37 (or lower) and off at 40 or higher
Idea here is - why run it 24 / 7 when water is holding full DO saturation with no risk of low DO and lots of seasonal trunover with wind, rain and snow and falling temps etc. And, it is set to keep the ice off. Anyway, we'll see how that works- always lots of learning to do.
I plan on raising it up in March to ON at 60 or lower and OFF at 62, to actually bring up the water temp closer to the optimum growth temp of 55-65- on those warmer days etc. Your thoughts?
