They are pretty much a way of growing plants in a hydroponic setup. They relay on the roots being emersed in water constandly and there is air that is supplied by an air pump and giving the plants the oxygen they need. Here is a basic plan for a bubbler system that I found a long time ago, but there are many variations you can use for this system, just use your imagination.

http://www.1stmarijuanagrowerspage.c...oponics-3.html