I guess I started this topic by talking with Bruce about potential "supercooling" of smaller (less than 5 acres)pond and lakes by aerating in the deepest part of the lake. I aerate several smaller lakes in NW Wyoming at about 8000 feet. 8-10 feet of snowfall and average temps of less than zero for 6-8 weeks. We had a landowner who reintroduced a pair of Trumpter swans on to one of his lakes. The lake was 3 surface acres, with a max depth of 16 feet. The only fish in the lake were Snake river cutthroat trout which had winter killed the year before. We set up a 1/2 horsepower system with two diffusers in the 15-16 foot deep range. We managed to keep an area in the lake open about 50 X 50 feet all winter. The swans survived, but we killed every trout in the lake. He has 3 other ponds, in which we put the diffusers in .5 x max depth. We did not lose a trout in the 3 ponds. We also work on a larger pond about 20 acres in size. In this pond, which had winter killed every year for as long as anyone could remember, we put four diffusers, run off two 1/3 horsepower pumps in the deepest part of the lake 13-14 feet. The reason we did this was the aquatic vegetation was prevalent in water less than 8 feet deep and the lake had been stocked with several thousand pounds of trout that summer. I felt it was worth the supercooling risk because of the BOD problem I knew we were going to encounter. We have not lost a fish in that lake in 3 years and now have rainbow trout over 7 pounds. I belive the size of this lake is the only reason it has not super cooled. I aerate several lakes in southeast NE and how I set up the systems depends on several conditions, but I have yet to have a fish kill because of super cooling. My point is if you are going to aerate, consult someone from your region, don't let someone in Florida design a aeration system for a farm pond in Iowa.
