Dual Airlift Pump

thingiverse

The Dual Airlift Pump allows you to 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 of course, no free lunch. The design is the same otherwise. A pair of downward-pointing tubes prevent air from forcing itself out of the airlift pump 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 the "U" in my first airlift pump was superfluous -- 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 makes 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, on the theory that 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 and the other keeps going, all else being equal, it probably needs more air.