Dual Airlift Pump

thingiverse

The Dual Airlift Pump lets you water two separate things from one airlift pump, with a part just as small as my single airlift pump. It requires twice as much airflow, naturally - there's no free lunch. The design is the same otherwise. A pair of downward-pointing tubes prevent air from forcing its way out of the airlift pump in the wrong direction. They can be straight or coiled as long as they point down. Sources at http://burningsmell.org/3d/airlift/ How I Designed This I realized that the "U" in my first airlift pump was unnecessary - air that forced its way to the bottom would just rise and escape out the other side of the U. It works just fine as a straight pipe, catching and holding momentary excesses of air. Cutting the U in half creates two reservoirs, and nothing's needed to hold the other side of the U any more. I used that spot as another airlift chamber. I also put the air channels into the edge of the tube instead of the middle, figuring it would cause more turbulence. The dual pump definitely works. A big fish bubbler, a 2 liter pop bottle, 2 cans, some straws, and a lot of aquarium tubing were lashed up to show that the amount of water pumped is pretty close to the same on both sides. You need twice as much airflow to run a pair of pumps, of course. If one side stalls while the other keeps going, all else being equal, it probably needs more air.