See the 1999 Hydroponic Garden. 

If you would like to start your own system hydroponic system to grow crops like lettuce, click on the link below or download the file (Word format).

Simple Hydroponic System (html)

Simple Hydroponic System (Word 6.0)

The link below will take you to photos of a simple floating bed system I use for growing lettuce year round.

Photos of the Simple Hydroponic System in use