It turned out rather nice and provided good drainage for any rain water coming off the greenhouse.
I have also included a few pics of the raft system plants to show some of the growth that is going on.
I have five varieties of lettuce, which include Romain, and bibb. Just wish I had more growing.
I also have squash and cucumber plants in the raft systems which seem to being doing "Just OK", but really haven't taken off yet.
Here is a quick overview video of the entire greenhouse setup, inlcuding the DWC Raft and new nursery plant rafts.