Bill, you sound like you understand this quite well. I have had good luck running my bottom diffuser all winter but only 8 hours a day. My situation is different I guess from you or Muddy since I live in central MN where the ice gets 2 feet thick on pond. Do your ponds stay open all winter? I feel I need to aerate if only so that I don't get fatal buildup of things like ammonia in pond. When it gets real cold I can only keep a 6 inch hole open but at least the aerator gets gases out. I'd like to stop running the thing all winter but don't know if I want to mess with what's been working.

Gotta get back to fishin!