Hello there guys,
Thought that I would chime in on this topic. I just wanted to let you know that I have used the Koenders Windmills as well and I agree that there stones are not efficent. I have gone as far a changing the hose barb to a 5/8 barb and ran self sinking air line from the unit to a regular diffuser that does produce a much finer bubble. This seems to work well. Also the anchors that they provide seem to be very adequate. We have a 20' windmill in the front of our shop that has seen some very strong winds and have no problems with the stability of the mill. We really just have the mill on rail road ties that are set slightly in the ground.
