Hi Buffer ~
I agree with Todd ~ I think your pond is too deep to experience a winter fishkill. I also don't think a windmill would be of much benefit. Windmills struggle to keep ice open in the extreme cold, and even for summer aeration you would definately need more than one windmill. I am definately not a stocking expert, but I imagine they are still alive in your pond, it's just that you have a big deep pond.
