MN, I'm also in MN. I have a 1/2 acre pond and the crappie do great. Problem is that they do too well. I made the mistake of putting 100 crappie in my pond and now I spend all summer trapping hundreds of little ones so they don't overpopulate. I don't think I could fit enough predators in the pond to control them. Unless your pond is large and deep you will need aeration to avoid winter kill I think. With a bottom diffuser in my pond running 8 hours per day I have not lost a single fish that I know about. I have turned the aerator off for periods of time and notice that if you have much organic matter in the pond you will very quickly get high levels of hydrogen sulfide or whatever it is that causes the rotten egg smell. Then you really have to be careful what you do. Best to keep aeration all year. I have had very good luck with my BG.

Gotta get back to fishin!