Gurgling Bucket: How's it work?

[Bucket]

Gurgling Bucket: How's it work? In the diagram for the air pump bucket it shows a 36 inch hose from an air pump going into the reservoir attached to a 1/4"tee. The "up" part of the tee has a 28 inch hose attached to it that goes up and over the medium. The third end of the tee is open and vents into the nutrient tank. How does this supply nutrient up to the medium? If air is pumped into the tee, it will blow into the nutrient and bubble up to the surface of the fluid in the tank. How does the solution rise up the 28 inch hose to the top of the medium?