For a Gast compressor check out Stoney Creek Equipment company. The compressors are made in Michigan and Stoney Creek is also in Michigan. I was purusing through an Aquatic Ecosystems catalog the other day and their systems are way overpriced! My God! I think that may be why some folks think they can't afford the systems.

The rotary vane compressor I have was wired ready to plug in at 120 volts. You can specify 220 if you wish, which would save you electricity as in ruduced amps. That is if you have 220 available.

You can do what you want with the airline(s) and diffusers, but you're wasting your time trying to match a good quality compressor that is made just for what you are trying to achieve. You'd proabably be wasting efficiency and paying through the nose on electricityy bills with a homemade version.

Here's Stoney Creek's link:

http://www.stoneycreekequip.com/form/aeration_lake.htm

If pigs could fly bacon would be harder to come by and there would be a lot of damaged trees.