Hey there dirtyedge ~ welcome to Pond Boss! A windmill would probably be adequate for your size pond. The main draw back to a windmill system is that there may not always be enough wind to keep the diffuser bubbling and those hot still summer days is when you need the aeration the most. If you don't get enough air, then your pond could become under-aerated and that could cause more problems. I believe Outdoor Water Solutions has an electric back up compressor in addition to the windmill, so you wouldn't have to worry about there not being enough wind. The bottom line is that an electric system is much more dependable. In the summer you would want the diffuser in the deepest location, but if you want to run it in the winter you'll need to relocate the diffuser to shallower water to prevent the water becoming too cold for the fish. There are many benefits to having a well aerated pond - just make sure you do your homework and read up ~ there is a ton of great information regarding aeration on this website.
