edit 7279,
Since your talking about spending $900+ I think you should keep in mind what you're hoping to accomplish.

If your .25 acre pond has an avg depth of 8 ft, it contains approx. 650,000 gal of water. Others have determined that successful aeration would be lifting that volume of water once per day.

A critical part of your system will be the diffuser and its efficiency in lifting water. For example, the Vertex XL1 diffuser will lift 1250 gpm at 8 ft depth when supplied with 1.0 cfm of air. That's 75,000 gal per hour or 8.66 hours to lift your 650,000 gals.
The diffuser shown in your proposed system seems to me to be a weak link.

As I see it, you need:
(1) An air pump rated for continuous duty that can supply 1.0 cfm at the depth (pressure) your diffuser will operate in.
(2) Power to operate the pump for the minimum req'd time and, if DC, to fully recharge the system for its next use.
(3) The most efficient diffuser you can source.

Like yourself, I originally thought I wanted a windmill powered system. Reading PBF convinced me otherwise. I researched solar-powered aeration systems and decided they were far from affordable or bullet-proof. In 2014 I installed twin Vertex XL2 diffusers powered by a Gast 0523 rotary vane pump. The pump sits in my barn and pumps air 500 ft through buried 1" dia Poly pipe to a homemade manifold at my 1 acre pond. System runs 24 x 7. The electricity to power the system costs about $15/mo.

Last edited by dg84s; 04/04/15 08:03 PM.