It gradually lifts water using compressed air. It uses standard 1/4" aquarium tubing and pumps and is small+streamlined enough to fit through a pop bottle neck. It can lift water over five feet, using the cheapest air pump petsmart had... It could be useful for watering plants on a timer. Thank you gswatts for the inspiration! Hose barbs modified from the ones by cgipeart for his water rocket.It prints in several parts, the main body and the hose barbs. Print in ABS, glue together with ABS pipe cement. There are two fitting on top. The straight-through pipe is the outlet, which belches air and water upwards. The one that stops halfway is the air inlet. There's a small connection between it and the straight pipe to let air into the stream. The fitting on the bottom is the inlet. You should add a length of tubing to it -- it stops air from bubbling out of the bottom too easily if the top tube becomes "full". Somewhere between half a foot to a foot of tubing seems to work for me. Loop it back up to the clip on the side.