NFT stands for “Nutrient Film Technique,” which I think traditionally involves styrofoam rafts holding netpots and floating on water in a hydroponics operation. In this case, I have 3″ netpots filled with shale that was too small for the growbeds, but still large enough to stay in the netpots (great use of what I thought was useless except as soil amendment). I have 20 feet of 4″ PVC pipe going out away from the growbeds, then a U-turn and 20 feet back, with holes every 10 inches. This gives me about 45 usable holes for plants, plus one over the drain standpipe.
Here’s the building process: cutting, painting, bolting, gluing…
Here is a view of the water input (back, hose from GB 2 drain) and drain (front, hose to GB 2 sump tank):
Strawberry plants in place:
Nat Jr inspects the drain standpipe, watching it burp and splash.
Nat helped me fill in the empty holes with neoprene-capped netpots, which should help prevent evaporation on holes that are not in use. The garlic chive plant is in the hole closest to the water input.
At first I had issues with the drain – leaked around the brass fitting into the PVC when I did a water test. I drained it all and sealed it with silicone. After that, I had issues with the drain hose not draining fast enough, and had to play with the height of the drain standpipe to get a decent siphon, but now I don’t think it’s in danger of overflowing out the netpot holes anymore. Now the single biggest risk to this system: a 3 year old boy.
Finally, a video: