Good point. Yes a diffuser could be placed at some shallower depth than the maximum depth. Thus all the water above diffuser depth would be mixed and aerated. The more of the pond volume that can be circulated the less chance of a fish kill will occur. For an average 0.5 ac MI pond expect the pond to mix naturally down to around 6ft maybe 7ft deep. Everything deeper will likely be devoid of oxygen at a minimum of July-August especially after year 3 as the pond ages and becomes more eutrophic.
A 1/2 acre 20+ft dug pond has a wide V shape. A large majority of the water is in the top aerated 15-16ft, which means the water volume deeper than 16ft will have low volume and minimal influence on the aerated portion, if the pond turns over and has anoxic water in the deepest part of the pond. Thus fish kills should be very rare.
Last edited by Bill Cody; 01/16/15 11:24 AM.
