Re: I would appreciate info on Aeroponics.

The Land Exhibit at Walt Disney World's EPCOT Center in Orlando, FL is 
famous for aeroponics systems (Murphy, 1984). They use brass misting 
nozzles, PVC pipe, a pump, solenoid valve, reservoir, and time clock to 
spray a nutrient solution over the plant roots every few minutes. A hanging 
PVC plastic cylinder or wooden box with holes in the top supports the 
plants and allows room for the root system. You would probably want a 4 by 
4 foot system to be from 1 to 4 four feet deep (depending on size of root 
system) of marine plywood painted on the inside with a nontoxic waterproof 
paint and white on the outside to reflect heat. You would want a drain to 
allow excess water to escape. A cheaper system might be made using one or 
more cool mist humidifiers instead of the misting nozzle, pump, solenoid 
valve and time clock. A cardboard box lined with a plastic garbage bag 
might substitute for a plywood box.

The big disadvantage of aeroponics is that if the electricity or pump fails 
or the nozzle clogs, the plants can die from lack of water in less than an 
hour in sunny weather. For inexpensive solution culture systems and 
nutrient solution recipes for school hydroponic projects, see Hershey (1994 
and 1995).

I believe NASA had an experimental aeroponic system with plant shoots on 
the inside of a drum that spun to create artificial gravity. It's on the 
cover of Murphy (1984). I believe they gave up on that system because the 
nutrient solution mist would go everywhere in the microgravity of space. 
NASA more recently experimented with a porous tube hydroponic system in 
which the nutrient solution was under tension in porous tubes (Dreschel and 
Sager, 1989).


References

Dreschel, T.W. and Sager, J.C. 1989. Control of water and nutrients using a 
porous tube: A method for growing plants in space. HortScience 24:944-947.

Hershey, D.R. 1995. Plant Biology Science Projects. New York: Wiley.

Hershey, D.R. 1994. Hydroponics for teaching: history and inexpensive 
equipment. American Biology Teacher 56:111-118. 

Murphy, W. 1984. The Future World of Agriculture. Danbury, CT: Grolier