Hi Bassponder~
Hopefully they recomended a bottom diffused aeration system. The surface type won't get oxygen to the bottom of your pond. There is a wealth of information on this website regarding the different types of aeration. Because of the round shape of your pond, a single diffuser will give you the aeration you need to protect your fish and improve your water quality.

Sue Cruz
Vertex Water Features
www.vertexwaterfeatures.com