Basic Hydroponic system - NFT System (5/6)
Today, we will go over the Nutrient Film Technique (NFT) system.
The NFT is a popular hydroponics system for home growers and is usually used to grow small, fast-growing plants such as lettuce. Commercial growers also often use NFT systems to grow various kinds of herbs and baby greens. The advantage of an NFT system is that the plant roots are properly exposed to the oxygen, nutrients, and water they need. The major disadvantage of NFT systems is that they are sensitive to power outages; if the nutrient solution stops flowing to the plants, it isn’t long before they begin to wilt and die. Therefore, it is important to put preventative measures in place to protect your plants against this scenario.
How It Works
There are several ways to you can design an NFT system, but the basic principle involves using a shallow stream of nutrient solution through tubing to provide nutrients to the roots of the plants. The solution is pumped from the reservoir through a larger tube that is connected to several small ones. Each small tube is used to run the solution to each side of the channel where the plants grow. The shallow stream of nutrient solution flows from one side of the channel to the other, using gravity, as the channel is slightly sloped. Usually, the plants are in small baskets in holes on top of the tube, suspended above the nutrient solution in the channel. The roots hang down into the nutrient solution stream in the channel. The excess solution is then drained back into the reservoir, where it is re-circulated once again.
While the stream of nutrient solution is shallow, the roots are completely moist because they are able to wick up the solution due to the humidity in the growing channel. The plants also have access to plenty of oxygen through this system from the air surrounding the channel and tubing.
Typically, commercial growers must use specially designed NFT systems that feature lengthwise grooves on the bottom of the channel. This allows the nutrient solution to flow beneath the root and keep the fluid from pooling too much. Home growers most often use rain gutter spouts to address this problem, as they have similar grooves, but are much less expensive.
Building Your Own System
To build a NFT system, you will need:
- A container to act as your reservoir
- A fountain pump
- Tubing to take the water from the pump to the growing tubes
- Growing tubes in which the plants grow
- Small baskets to grow seedlings
- Growing medium