This is a interesting topic. I too have wondered about super cooling in that I have a very small 1/10 acre backyard pond in NW Ohio that I have been discussing doing a put and take of trout this winter with the experts here. I use a variation of the RC 51 system.
I just last week suffered the very cool temps to swim out and move the 3, nine inch diffusers to the a depth of 4'. I plan to continue running the system 24/7.
I have personally caught 100's of pounds of steelhead and browns in northern rivers that run so swifty they never freeze despite temps being in the single digits for days at a stretch. This in mind I have doubts that super cooling is a concern for me. I have spoken to several folks and the messages are mixed.
I will keep you guys posted as go through the winter.
