Here, we’re building a prototype hydroponic nutrient film technique (NFT) farm. The goal is to be able to have a constant harvest of 20 plants per week. This requires 20 plant sites (at least) to be available to each phase of the growing cycle.
How to begin?
A lot of graph paper. And some time.
Then, basically, I went and got a bunch of pipe and tubing, combined it with pumps, aerators and valves. That was the easy part. Figuring out the design, how things (water?) flow, channel, wave and suck (believe those are all technical terms) was the hard part.
It isn’t just building something that will make the plants happy – a good system requires ease of maintenance as well. Floor level drains, easily accessible valves, standard fittings to fill/drain reservoirs, and simple things such as black-opaque tubing to keep algae growth down is necessary.
This is a nursery channel in construction. The nursery channel is a high-density NFT-like (nutrient film technique) channel, but it really doesn’t entirely use NFT principles. The nursery is the step following the seedling tray stage. It allows the plants to expand their roots in a more efficient condo-style accommodation, until they are ready to plant in the finishing channels.
This nursery channel is 5′ long and has 23 plant sites.
Here you can see two nursery channels adjacent to a finishing channel. The finishing channel has about 10 plant sites to the nursery’s 23. It has to be further spaced to accommodate the growing plant.
One light installed above the nursery channels. This is a 4′ long 4-bulb T8 housing. It will provide light for just over half the lower nursery channel. The upper section will be another 4′ housing that will provide seedling and nursery light. All the lights are on height adjusters, they start very close to the plants and move up with them.
The longer-term goal is to have the channels on adjusters as well, in order to stack multiple channels and lights atop each other to maximize the growing capacity for the available floor space.
The nutrient (water + fertilizer) reservoirs are shown here, as well. The lower (right) is where the pumps (water and air) reside. The nutrient-filled water is pumped up with one tube into the upper reservoir, where it is then distributed to the growing channels. Excess water in the upper reservoir is returned through the other black tube. This allows the pump to run at maximum capacity (greatest efficiency and less wear) all the time, while any excess capacity at the top is simply gravity-drained back into the reservoir, further adding oxygen and preventing stagnant water.