I am also going the way fish n chips is, with seasonal RBT. However, I couldn't resist getting a few RBT this spring to see if they will make it through the summer with aeration going 24/7 (so far they are doing great, but the hot summer has not yet kicked in). My BOW is approximately 12' deep at center, 1 acre, I have 3 dual disk vertex diffusers with a Gast 1/3 hp compressor. Your ponds may also be ground water supplied, which is similar to spring fed, either one does tend to get water level fluctuations like mine, sometimes as much as 5' difference from full pond to low, spring fed may have much cooler temps, and less of a funnel effect. What part of WI are you looking at, maybe I can offer some recommendations on suppliers if you are near me?