Whisper Aeration Air Pump
$ 29.99

This pump is perfect for aerating your wort! This pump provides reliable, quiet operation and has a 1/8" barb output. You can use this with some simple tubing, an inline filter and a diffusion stone to make an economical aeration setup.

Using this pump with a 2 micron diffusion stone you can expect adequate oxygen levels in 30 to 120 minutes. But, even 5 minutes of aeration with this pump is better than shaking a carboy.