1. Aeroponics
1. The plants are raised in a system that provides a continous mist on their roots

2. Ebb and Flow
1. The plant growing container is alternatly filled with solution then drained. Can be a very simple system made of two buckets and a hose or very complex using pumps and timers, even computer control.

3. Raft
1. A good basic system in which the plants are floated on the solution using some type of raft. Styrofoam sheets are most common. A common method for growing lettuce in which the rafts of lettuce are moved along a long tank as they grow.

4. Nutrient Film Technique (NFT)
1. A constant flow of solution is running in a trough into which plants roots are placed. Usually a recirculating system but can also be a once through system with the affluent discharged onto other plants.

1. http://www.carbon.org
2. http://www.superhydro.com/index.php
3. http://www.hydronov.com (floating raft system)

http://us.f1.yahoofs.com/groups/g_3025762/Hank's+Solar+House/__tn_assembled+mini+greenhouse.jpg?bc0qLvBBqtWswHO0

This was an attempt to add a picture link