Pond Boss Forums INTRO Questions & Observations Circulating 2 Acre Pond w/ 3000 lpm Air Lift Pump

Air lift technology can move lots of water economically the technology has been around a long time. Back in the 1980's, Elmer Hedlund in WI used it with a home made diffuser in a large diameter pipe to move water in a small stream connected to his pond to allow walleye to spawn in the stream.
In fertile systems expect 1"(2.54cm) organic accumulation per year. Much of this in the deepest basin can be decomposed or biologically processed if the sediment layer has ample dissolved oxygen and many thriving detrivores. I have learned that pine - spruce needles can blow a lot longer distance that I once thought.

Michigan State Univ Extension, Managing Michigan Ponds ror Sport fishing says "Having a depth of 18 to 20 ft is distinctly better than 15ft and 25 ft is even better in areas with harsh winters. Cost can be a limiting factor. If money is not available for at least 15 ft depth it is best to save up money until there is enough available money rather than creating an inadequate pond and a disappointing fishery. The recommendation of 10-12 feet for depth of ponds are based on conditions in more southerly states."

MI DNR - Fishing & Swimming: A clean water supply; adequate size and depth, a minimum size of 1/2 to 1 acre is preferred with as much of the pond as possible having a water depth of 15 feet or more; side slopes of 1:3 (1 vertical foot to 3 horizontal feet) to discourage aquatic plant growth; side slopes in the swimming area of 1:4 for safe entry and exit; irregular shoreline for fishery habitat; protection from storm water runoff which can carry sediment and nutrients.

IMO if the pond can receive at least limited bottom aeration during winters with deep extended snow cover the pond depth does not have to be greater than 15-18ft deep.