What's your defination of economical? Do you want something that doesnt' cost much up front? Do you want something that might not do as well of a job (I say "might" because parts of the system have not been tested to see how many GPH it moves)? How much sweat equity are you willing to put in to making a system yourself? If something breaks, can you fix it yourself?

Like what has been said before. There's MUCH more that goes into an aeration system than putting something in the pond that blows bubbles.

If you are willing to do a lot of the work yourself in regards to putting a system together yourself, sourcing all the pieces/parts, etc. then look at the DIY RC51 system that he built and chronicled here.


www.hoosierpondpros.com

[Linked Image from lh6.ggpht.com]
http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).