Step 1: You'll need a wicking material
Cotton rope is the easiest, however it has the disadvantage of rotting, so I borrowed some "nylon" rope from a tree guy i know. What I got is a hank of synthetic rope, probably polyethylene. Then i tested it's wicking ability, both washed and unwashed. Washing it really help. I measured the absorption at 1ml/Hour/wick
Step 2: Now that you have a wick
Mix up a bucket of nutrient solution, punch a hole in the top, thread the wicks (I decided to use four) through and snap the lid on the bucket.
Step 3: Now the grow container
I cut down a couple of 5 gallon plant pots and forced on inside the other so that the media wouldn't wash out the holes. Then threaded the wicks up through the bottom hole and spread out the wicks.
Step 4: Finally
I put an inch of vermiculite in the bottom of the grow container to ensure good wickability, and then filled the rest of the container with 50/50 vermiculite/perlite.
Pre-moisten the media, sprinkle with lettuce seeds and set in the sun.
Here's 4 weeks growth, could have been better, poor nutrient mixture.