I have one of the 230v surface aerators and 300' of line in my 3 acre pond. It creates ripples over the entire pond surface with no problem.
I have to use surface aeration because my pond has geothermal tubing in the bottom, but I think the shallow nature of your pond would benefit greatly from one or maybe two them. The surface aerators move a great deal of frothy water compared to my 220v 1.5 hp pool pump that runs a fountain in the pond. That's like a squirt gun compared to 3' long super soaker in a water fight. Absolutely no comparison.
