Growing Hydroponic Lettuce with Nutrient Film Technique (NFT) Systems...A Sustainable Way to Grow Fresh Greens
Tired of sad, wilted lettuce and greens that traveled hundreds, even thousands of miles to end up on your plate looking less than fresh? Are you interested in growing your own healthier, fresher lettuce, pesticide free, year-round, farm to table? You can grow lettuce, herbs and other leafy greens year-round without soil in a hydroponic Nutrient Film Technique (NFT) system. You can grow in a greenhouse, a garage, or just about anywhere. In this blog, we'll explore what an NFT system is and its advantages, what’s needed to set one up, and some helpful information to get you started.
NFT Systems at a Glance
NFT systems typically consist of a series of channels that are set at a slight angle to allow a thin film of a nutrient-rich water solution to flow continuously along the bottom of the channel. The nutrient solution is pumped from a reservoir to the highest end of the channel. It flows down the channel, creating a shallow film of water that continually bathes the roots of the plants. The roots absorb water, oxygen, and nutrients directly from the film, enabling the plants to grow efficiently without the need for soil. The continuous flow of nutrients enables the plants to grow rapidly, and you can even harvest multiple times from the same plants.
Advantages of NFT Systems
- Water Efficiency: NFT systems are incredibly water efficient. The nutrient-rich water solution is pumped from the main reservoir to the channels and creates a thin film of nutrient-rich water that continually flows down the channel and is then returned to the reservoir and recirculated. This minimizes water waste, making NFT an eco-friendly choice for lettuce cultivation.
- Space-Saving: Ideal for urban gardeners and those with limited space, the shallow, horizontal channels used in NFT are stacked vertically, and take much up less room than traditional soil-based gardens. You can grow much more in a smaller space. For example: 2’x4’ floor space could have 32’ of vertical growing space.
- Pesticide and Herbicide Free: Since NFT systems are soilless, they are less susceptible to soil-borne diseases and guess what, no weeding! No need for pesticides or herbicides when growing soilless indoors.
- Faster Growth and Higher Yields: Plants in NFT systems typically grow faster with higher yields due to continual access to optimal nutrients and oxygen. You can enjoy fresh lettuce with a shorter grow cycle.
- Year-Round Growing: NFT systems allow you to grow lettuce indoors, enabling you to grow and harvest fresh greens all year long, regardless of the weather outside.
What you need to set up a Nutrient Film Technique (NFT) hydroponic system:
To set up a Nutrient Film Technique (NFT) hydroponic system, you'll need several key pieces of equipment and supplies. Here's a list of the essential items required for an NFT hydroponic system:
- NFT Channels and Channel Covers: These are the primary components of the NFT system. They are typically made of PVC, plastic, or other materials and are designed to hold and transport water. The covers have pre-drilled holes for a net pot to sit in. While covers are not required, it gives the plant more stability, but also makes it harder to see if there is any root growth clogging the channel later on.
- Main Reservoir: This is a container that holds the nutrient solution and should be large enough to provide an adequate supply of nutrients to the plants, especially when they get larger and consume more.
- Submersible Pump: The submersible pump is responsible for pumping the nutrient solution from the reservoir to the top end of the NFT channels. The flow rate of the pump should be adjustable to control the flow of nutrient solution.
- Tubing and Fittings: You'll need tubing to connect the pump to the NFT channels and fittings to ensure a watertight connection. Ensure the tubing is appropriate for hydroponic use.
- Net Pots: These are mesh-like plastic containers that hold the plants and allow their roots to dangle into the nutrient film inside the NFT channels. These are placed inside the hole in the channel lids.
- Growing Medium: NFT systems typically use a sterile and inert growing medium to support the plants and their roots. We use Rapid Rooter and can place them directly into the net pot in the channel after seeds have germinated. Some other options are rockwool cubes or clay pebbles.
- pH and EC/PPM Meters: pH meters are used to monitor and adjust the acidity of the nutrient solution, while EC (Electrical Conductivity) or PPM (Parts Per Million) meters help measure the concentration of nutrients in the solution.
- Nutrient Solution: You'll need to make a hydroponic nutrient solution using nutrients specifically formulated for the type of plants you're growing. Different plants have different nutrient requirements, so choose the appropriate formula. NFT systems require regular maintenance, including checking and adjusting the nutrient solution often.
- Timer or Controller: To control the on/off cycles of the submersible pump and manage the flow of the nutrient solution you will need a timer.
- LED Lighting: If you're growing plants indoors, you'll need suitable lighting. LED grow lights are commonly used for indoor NFT systems and are made to fit channel systems.
- pH Adjustment Solutions: These solutions are used to raise or lower the pH of the nutrient solution as needed.
- Air Pump and Air Stones (optional): Some NFT systems utilize Air Stones to increase dissolved oxygen which will enhance root health and promote better growth.
- Thermometer and Hygrometer: To monitor the temperature and humidity levels in your growing environment.
- Supporting Structure: If you're growing plants vertically, you will need a supporting structure such as a metal rack to hold the NFT channels and plants.
How to Grow Hydroponic Lettuce with NFT Systems:
Set Up Your NFT System
- Purchase or build your NFT system.
- Ensure the channels have a slight slope (1:30) to allow the nutrient-rich water to flow over the plant roots.
Select the Right Lettuce Variety
- Butterhead, Romaine, and Bibb lettuce varieties are excellent choices for NFT systems due to their compact growth.
Germinate the Seeds
- Start your lettuce seeds in a separate germination container using a hydroponic-friendly growing medium - we use Rapid Rooter plugs.
- Once your seedlings have started to grow, place them in a suitable sized net pot inside the NFT channels.
Maintain Nutrient Solution and pH Levels
- Regularly check and adjust the nutrient solution to maintain the proper pH and nutrient levels.
- Top up as needed.
- Lettuce prefers a slightly acidic environment with a pH of around 6.
Provide Adequate Light
- Ensure your lettuce plants receive 10 to 12 hours of light each day.
Monitor and Harvest
- Keep a close eye on your plants, checking for any signs of nutrient deficiencies or diseases.
- Harvest the outer leaves as they mature, allowing the center to continue growing.
Clean and Maintain the System
- Regularly clean the NFT channels, pump, and nutrient reservoir to prevent algae or bacterial growth.
- Change nutrient water solution in reservoir weekly.
- Flush the entire system every so often with a light bleach solution and then repeatedly flush it through with clean water.
What else can I grow in an NFT system?
Besides so many varieties of lettuce, Bok Choy and Pak Choi are another great NFT crop choice. Basil is another good crop for NFT hydroponic gardening, as well as other herbs like Parsley and Cilantro.
With hydroponics you can grow your own produce and plants - heathier, faster and with higher yields than traditional farming. Growing hydroponic lettuce in an NFT system can be a rewarding and sustainable way to enjoy fresh greens and eat healthier. NFT systems offer a reliable, efficient, and environmentally friendly solution for hydroponic lettuce farming. Following a well-designed plan, keeping an eye on your plants, their roots, and proper maintenance will help ensure a successful and bountiful NFT hydroponic setup.
Check out our website www.artisuntechnology.com for other hydroponic growing methods include:
Artisun Technology is a supplier of innovative hydroponic systems for growing indoors and outdoors.