bc, how deep is your pond, how large is it and what shape is it?
Shallow ponds, less than 6 feet deep, can sometimes be aerated more effectively with surface aerators. One of the major draw-backs is that they only draw water fronm the top 5 feet of the water column. However, bottom aerators have their draw-backs as well. The shallower the water is, the less water that bottom aerators move. So, there is a point, somewhere around 5 feet (depending on size and shape of pond), where it is better to go with surface aerators than bottom aerators.
Also, if you have a problem with duckweed, or certain other types of surface vegetation, surface aerators can be a great help in fixing the problem. Don't get me wrong, I install 10 bottom aerators for every surface aerators, but certain situations call for surface aerators.
Mike Robinson
Keystone Hatcheries
