Two DWCs under the lights.
 

http://img856.imageshack.us/img856/2534/18apr119.th.jpg


Mesclun mix growing like crazy on the left and 20 day old Simpson on the right. Keeping a continuous crop is pretty easy once I captured all the timing and growth rate data.

What kind of light are you using?

It is a simple rig of three T8 48" dual shop lights fashioned together to create a 6 light system. It is raised via pulleys for the photo. Normally the 6500k bulbs are within an inch of the plants. The fan removes what little heat is generated from the tops of the plants to prevent any bolting.

It works very well for lettuce and starts, but I would not use for peppers or tomatoes through maturity. Maybe a T5 H.O., but not this T8.