I was wondering today while trying to grow more plants in a smaller space, can I stack another rail system on top of the one I currently have? We shade the lettuce to keep it cool and resist bolting. This time of year to get good tasty quality lettuce we learned that slow growing is best.
So, and I know we are just talking here, but is it feasible to stack one nft system on top of my current system, alternating the rails so that light filters past the top ones down? I will need a more powerful pump for the top system. I think my current resivour will be large enough.

What do you think? I have seen u tube videos similar but I don't know how well they work?