How to do an irrigation system for "pallet gardens" that is driven by an aquarium bubble pump. Approx 20 litres per hour of air is needed for each airlifter. Bubble pumps seem to start at about 60 litres per hour. This reliably pumps to any height between 6 inches and 6 ft. (and probably a lot higher too). 15cm to 2 meters pumping height. I have been using it since about 4 months now.