Dan P. Since your pond is larger your stratificaion layer is probably at the 10-12 foot level; maybe 14 ft. Get your test person out in a boat to test for the depth of DO drop off. Once you find the thermocline, your DO will probably go from 7 to 3 in about one foot drop and from 3 to 1 or zero in the next foot. If you have DO of 4 to 6 down to 10-14 ft your pond can do pretty good without aeration. Extended (5-8wks) Heavy snow cover will be your biggest problem in winter. Removing snow is the best thing to minimize winter kill in areas with severe winters.
With so many trees and little wind exposure a windmill would be a very iffy investment. I live south of Adrian about 45 minutes. I sell windmills and air compressors for aeration. You are welcome to come and see both in operation. PS Come on a windy day. BC
