To those of you interested in Micro ponds, this post is to provide the link to a picture of the finished product(first time to build one of these and DIY). You have to scroll down to the last picture, sorry.

The micro-pond is doing just great on the water circulation alone as Cary advised. No aeration. The fish thus far include 1 LMB, 1 F1 GG, 1 F2 GG, rosy reds, Gambusia, Tadpoles(ok not fish), gold fish and Koi. Many others yet to come. Just like in my ponds, the rosy reds (fatheads) are disappearing (only 5 left out of two dozen) and the Gambusia are increasing (10 fish with only 2 stocked).

http://www.meadowlarkponds.com/gardens.htm