building a new duck marsh this summer and i'd like to have an aeration system (de-icer) in place before the winter.

the marsh is less than 1/4 mile from electricity. i'm interested in keeping a 45yd (diameter) ice-free hole in front of the duck blind. i can make the "duck hole" 3' deep, but no deeper.

any ideas from the experts and/or first hand experience w/ de-icers from other duck hunters would be greatly appreciated.