Even though I bought some diffusers and am waiting for them to be shipped, I am still sold on the idea of using a regular air compressor.
You can pick up a small, portable type air compressor for around $100 - $150 at any home improvement store. For that matter you can pick up a used 2 cylinder like I have on Craigslist for around $125 - $200 depending on age and condition.
Unlike the vacuum pumps I looked at, my compressor only runs when there is demand. If there is no demand it does not run at all. It ONLY recharges the pressure tank. It has a 3.5HP motor. It also has a separate line pressure regulator right off the tank. If you wanted you can get them separate and hook up a "T" so you could use the compressor at full pressure (for shop or tools) and have the pressure regulator on the air diffuser side. This provides the best of both worlds.
Also, I see a LOT of people getting started who need / want to know how big a pump they need, how much CFM, how much pressure, etc., etc., etc. This ability to manually control the pressure at nearly any reasonable range seems like it solves that issue. I have no doubt my compressor could run 10 or more commercially available diffusers at fair depths too. Might be a bit of a load but it could support it. Anyway, I had the compressor and figured it solves the problem. For those starting out it might, or might not work. Need to check the cost of air hose and here in MN where it gets REALLY cold in the winter you ONLY want rubber.
