Here's help with raft system and materials

Here is a link that might be useful: Cornell Lettuce

Hi, If you haven't started building your system yet, take a look at how lettuce did in a simple to make system using 2X4s and a plastic tarp. To answer your question, I have used a lot of styrofoam with good results. Only problem I had with it was that algea love's it, and it tends to get covered with it quickly. You can also see how I used the styrofoam in the pictures on the link below. good luck, chuck

Here is a link that might be useful: lettuce growing in simple system

Swimming pool noodles!

Buy a noodle and cut a bunch of 1.5" disks out of them...

The tricky part is figuring a way to bind two or three of them together at a time. Once you've done that, just keep binding little clusters of them together until youÂre satisfied. I don't think they would be stable enough on their own. That could be a way to go?

ThatÂs a very unique & refreshing idea, rugby10. Maybe they could be tied together with nylon ties. I have seen them both available at the dollar store, as well as large containers that would work as a mini pond. You could get a whole setup for about $3.00.
Remember when growing lettuce during low light times excess nitrates can be absorbed.