Here's my 2 cents. I have looked at alot of diferent cheap ideas for aerating, and have come to the conclusion that cheap is not always better. I have tried cheap compressors from garage sales, cheap compressors from motor shops, and have found that they dont last running 24/7. I did however try an air pump that came out of a septic aeration system, it is also the same type of pump that comes off an automotive engine for pumping air into the exhaust. The problem was that it was noisy even after I put it in an insulated box.
