Here's a good video which describes the idea. It's a slightly different Aquamaxx model but the concept is the same. Being able to purge this air is important as you'll get this bubble each time you add media.
<iframe width="560" height="315" src="https://www.youtube.com/embed/sT-cEMVif98" frameborder="0" allowfullscreen></iframe>
A few tips:
- If you have a feed pump, open the bleed valve and close the effluent valve which should push the air out the bleed valve as seen in the video.
- Alternatively, you can manually inhale the air out from the bleed valve as long as no lines are above water level (ie. allow air to come in).