I have a 27,000 gal pond in WI.
Do you know anything about using those pond breathers I know most folks hoop and heat but the shape of mine does not lend it self for it. My pond will freeze all the way across the top so the pond breathers are the only means of a gas exchange. I do have a dozen aerator stones pulled to the surface that will bubble.
By "pond breather" I assume you mean a concentration of high-flow air stones near the surface of your pond. The constant agitation at the surface keeps a hole ice-free.
As long as you maintain that high agitation and do not allow the ice to form a bubble over your hole, your gas exchange, though suboptimal, will be adequate to get you through the winter.
Covering the pond with a greenhouse arrangement is far superior. What about your pond makes this solution difficult?
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