DIY Nutrient Film Technique (NFT) Hydroponics for Home

Hydroponics is becoming increasingly popular among home gardening enthusiasts, and those looking to be more self-sufficient with their food supply. One of the most efficient and cost-effective methods for home scale hydroponics is the Nutrient Film Technique (NFT). This system allows you to grow plants without soil, using a thin film of nutrient-rich water that will be continuously flowing past the roots. This approach can easily be implemented at home with some simple tools, readily available materials, and a little bit of know-how. In this article, we will explore the benefits of NFT hydroponics and guide you through the process of building your own NFT system at home.

Table of Contents

Benefits of NFT Hydroponics

Nutrient Film Technique Explained

The Nutrient Film Technique involves creating a channel of nutrient-enriched water that flows over a plant’s roots, providing a constant supply of essential nutrients. The method promotes faster growth and higher yields compared to traditional soil-based gardening. It also reduces the risk of soil-borne diseases and allows for easier maintenance and harvesting.

There are many ways of achieving NFT and a system can be designed to suit a given space or production requirement. You can also be somewhat flexible with material choices depending on what is available in your area, although there are some recommendations that will make life much easier. 

Once set up and working, NFT requires some level of maintenance and monitoring. Just to keep things working as you expect, and to keep your plants growing rapidly! There is a bit of science and bit of art to this, and you’ll develop an approach that best suits your system and the types of plants you wish to grow.

Advantages of Hydroponic Systems

Hydroponic systems, including NFT, offer some great advantages for home gardeners, particularly for growing vegetables. They require less water than traditional gardening, making your food production less dependent on the utility water supply, saving you money. They can also be managed in a much more controlled manner compared to traditional farming, therefore reducing the need for pesticides and herbicides, providing you with healthier and more nutritious produce. Additionally, in the right location and with the lighting, hydroponics can allow for year-round gardening, as it is not dependent on seasonal changes.

Building Your Own NFT System

Step 1: Choosing the Right Location

The first step in building your NFT system is selecting the right location. Look for an area with good access to light (sunlight or growing lights) and easy access to water and an electrical supply.

Consider the size of your system and ensure you have enough space to accommodate it. You can be somewhat creative, but we recommend keeping it as simple if possible, to minimise construction difficulty. However, you can wrap your growing channels around walls, stack them in levels, keep them low to the ground, or high. You do have flexibility! So long as you can construct a support structure in the location that will precisely allow the grade of your channels to be set. This comes down to how handy you are and how difficult you want to make it.

Building your NFT in a greenhouse can also be a great idea, particularly in cooler climates. 

Step 2: Designing the Hydroponic Setup

Design your hydroponic setup firstly considering the available space, the number of plants, and plant type you wish to grow.  Plant type will dictate height requirement and the size and space required for your growing media. This will then dictate the type of channel material you use, channel spacing and height difference between them, should you layer them up. 

NFT requires a reservoir of nutrient-enriched water which is pumped to the top end of your growing channel(s). The water gravitates down the channel(s) at a depth sufficient for uptake by your plants, back to the reservoir. So you will need to consider where the reservoir is positioned, its size and how you will fill it with water.

The size of the reservoir needs to consider the number of plants, the daily uptake of the plants, the number of days of autonomy (without top up) you require, and a factor of safety of about 50%.

For small systems you can use 12V pumps powered by a small solar panel and battery can be used to circulate the solution through the system. You can calculate the required flow rate of the pump by determining the volume of the channel(s) and the turnover rate, ensuring you have adequate depth to feed the plants. As a rule of thumb, you’ll need to pump 1 to 2 litres per minute per channel. It is always better to select a pump with a greater flow rate capacity because you can throttle it back with a valve om the outlet side to you desired flow.

Sketch out the design and make a list of the materials and tools you will need and head down to the hardware store.

Step 3: Constructing the Support Structure

Decide whether you want a freestanding system or one that can be mounted on a wall or fence. You’ll need to construct a sturdy support structure for the NFT system that places the channel(s) at a slight grade towards your reservoir. You want the water to run easily, but while maintaining sufficient depth in the channel. 

The structure should be strong enough to support the channel(s), the water contained within them, pipework, and the plants when fully grown. That can be quite considerable weight. The structure must provide stability to the plants when they are growing also.

Think about convenient planting and harvesting height. Building the structure is the opportunity to make managing you NFT as easy as possible. 

There are many options for constructing the support structure. You could use a table or bench with props under one end of the channel(s). You could pipe or even scaffold material. You also bolt together a timber frame. Ultimately, you’ll choose an approach that is achievable for you at home, with the resources and tools you have access. It doesn’t need to be complicated, just functional.

An additional consideration might be trellis, or some other plant supports, if you wish to grow taller plants.

Step 4: Constructing the Channels

You will need to construct a channel of nutrient enriched water that supports the growth media and plants, and allows the plant roots to access nutrient flow. You can have one or multiple channels in parallel.

For most NFT builds, PVC pipe will be the easiest material for constructing the channel(s). You can use round 4-inch pipe if you choose. We recommend using 3×4-inch (approximately) rectangle section downspout PVC pipe. A rectangle profile will make setting the grade easier and simplify the planting holes.

Build the PVC channel(s) so that they distribute the nutrient solution to each plant. Ensure that the pipes are properly interconnected and provide a slope to allow for a consistent flow of the water.

You then need to drill the holes in the PVC channel(s) to plant into. You’ll consider what you want to grow to determine the spacing of these holes. When you are starting, we recommend using net cups which will dictate the hole diameter. The water level in the channel(s) should flow through the bottom of each net cup. When the plants are small, the growing media will wick the nutrient solution up to the roots. As the plants get bigger, their roots will become submerged. 

Step 5: Selecting and Setting Up the Reservoir, Pump, and Pipework

Choose a suitable reservoir that has the capacity you require. You can use a plastic bin or small plastic tank. Place the reservoir in position, taking care to ensure you can easily fill and drain it, you limit light to within the reservoir (important!), and the outlet can gravity feed the pump.

Install the water pump such that the reservoir outlet will gravitate to it, and it can access power. 

Connect the pipework to ensure a continuous flow of the nutrient-rich water from the reservoir to the channel(s). This pipework can be irrigation poly pipe, light weight tubing, or even a simple garden hose.

Step 6: Adding Nutrient Solution, pH Correction, Electrical Conductivity (EC) and other Chemistry

Hydroponic nutrient and other additions are dependent on the plants you wish to grow, and you’ll need to do a little research specifically for your situation. You’ll then need to do some basic chemistry as your plants grow to keep things in check. This is a big topic, and we will only provide general advice here. But don’t be put off by the chemistry. It can be as simple as knowing what you need and following directions on product labels. 

You’ll need to add a well-balanced nutrient solution to the reservoir. The ratio of water to hydroponic nutrient powder will depend on the nutrient you buy, and this will be provided to you on the product label. The nutrient label should show percentages of N-P-K, nitrogen being ‘N’, phosphorus ‘P’, and potassium ‘K’. There should be three numbers given. The plant type you grow will require the proportions of these macro nutrients to be in specific ranges and again, you’ll need to research this to make sure you select the correct N-P-K for your plants.

You may also add magnesium, which is commonly in the form of Apsom salts. This can support plant health but again, the amount added will depend on the plants you choose to grow. 

It is also advisable to add Calcium Nitrate powder in a ratio as per the product recommendations. Calcium Nitrate can significantly improve plant uptake of nutrients and can accelerate plant growth.  Follow the product instructions for your plant type. 

pH. Another big topic in itself! However just briefly, pH is a logarithmic scale that measures a liquid’s acidity. 7 being neutral, below 7 being acid, above 7 being alkaline. pH dictates nutrient availability to the plants and for most vegetables, you’re aiming for slightly acidic. Somewhere in the range of 5 to 7. Once you have added your nutrients etc. to the water in the reservoir, you should measure pH with a pH strip (readily available from gardening stores). You can then adjust the pH with addition of an acid or alkaline solution, also available at your gardening store.

Electrical conductivity (EC) is also an important parameter to measure in hydroponics. It however requires some more advanced instrumentation. It is essentially a measure of the amount of salt in the water. As the plants consume water and nutrients, the balance between the two can drift. EC gives you important information regarding that balance, and therefore what needs to be added to correct the balance over time. Look up the optimal EC range for your plants and try to keep within that.

You’ll want to get a basic knowledge of this chemistry and some basic tools to keep your system functioning optimally. But again, buying good quality nutrients and additives and following the product requirements gets you a long way.

Step 7: Germinating, Propagating and Planting Out

There are many ways to approach this and your plant type and specific NFT system will dictate the most appropriate growing media. When you are starting out, we suggest the easiest approach is to germinate your seeds in a vermiculite, perlite mix at a 50/50 ratio. You can do this directly in net cups that will be placed in the channel(s).

Depending on the net cups you have, you may find that some of the mix gets lost through the net and ends up in your reservoir. A small amount may be OK however this risks blocking your pump. If this is an issue, you can also try other media such as coco coir or a coco coir, perlite mix.

There are also plenty of other options to consider, each with their own pros and cons. Experiment and see what works best for you and your plants:

• Rockwool cubes
• Starter pellets
• Clay balls
• Plastic based media such as Sure To Grow
• or pucks 

You will have pre-drilled the holes in your channel(s) for planting. When the seedlings are mature enough you can transplant them into the NFT system. Ensure that the roots have access to the thin film of nutrient solution flowing through the system.

Maintenance and Troubleshooting

Monitoring the Chemistry

As discussed above, you’ll want to do regular monitoring of the nutrient levels, pH and EC in the reservoir and adjust them as needed to ensure that the plants are receiving adequate nutrition for healthy growth, within the specified ranges. This is an ongoing task which you will become good at in time, as you learn the system.

Dealing with Pests and Diseases

Implement preventive measures, such as using clean water and sterilized equipment, to minimize the risk of pest and disease infestation. Regularly inspect the plants for any signs of damage or infection and take appropriate action if necessary.

Root Problems

If you encounter issues with root health, check for any clogs or obstructions in the system’s pipes and channels. Ensure that the roots have sufficient access to oxygen and are not being overcrowded.

Light

You to consider light from two perspectives:

1. Ensure that the grow tray allows for adequate light penetration to promote healthy photosynthesis. Consider using reflective materials to maximize the light reaching the plants.
2. Avoid any light getting into the reservoir or anywhere the nutrient solution is flowing. You can easily create unwanted growth which can disrupt the system, block pipes etc. Do what you can to avoid algae growth.

A Final Thought

Building your own NFT hydroponic system is an exciting and rewarding DIY project that allows you to grow fresh and healthy produce at home. By following the step-by-step guide outlined in this article, you can create a highly efficient and sustainable garden using the Nutrient Film Technique, NFT. Thinking about where you construct your system can allow you to enjoy the benefits of year-round gardening, increased yields, and minimal environmental impact with this innovative hydroponic system. Happy hydroponics!

FAQs

Q: What is DIY Nutrient Film Technique (NFT) Hydroponics for Home?

A: DIY Nutrient Film Technique (NFT) Hydroponics for Home is a method of growing plants without soil in a hydroponic system. It involves creating a nutrient solution that flows directly over the plant’s roots, providing them with the necessary nutrients for growth.

Q: How does a NFT hydroponic system work?

A: In a NFT hydroponic system, a nutrient solution is pumped into a channel that is slightly tilted. The solution flows through the channel, creating a thin film that covers the bottom surface. Plants are placed in holes or slots in the channel, and their roots grow into the nutrient film, absorbing the necessary nutrients.

Q: What are the steps to build a DIY NFT hydroponic system?

A: The steps to build a DIY NFT hydroponic system are:

1. Choosing the right location
2. Designing the hydroponic setup
3. Constructing the support structure
4. Constructing the channels
5. Selecting and setting up the reservoir, pump, and pipework
6. Adding nutrient solution, pH correction, electrical conductivity (EC) and other chemistry
7. Germinating, propagating and planting out

Q: What is the purpose of a nutrient solution in a DIY NFT hydroponic system?

A: The nutrient solution in a DIY NFT hydroponic system provides essential nutrients to the plants, allowing them to grow and thrive without soil. It is a complete solution that contains all the necessary elements required for plant growth.

Q: Can I use any type of growing media for a DIY NFT hydroponic system?

A: There are various types of growing media that you can use in a DIY NFT hydroponic system, such as clay pellets, rockwool, or coconut coir. The growing media provides support to the plants and helps to anchor their roots in the nutrient film. You’ll need to consider the plants you are growing the specific NFT setup you have when selecting the growing media.

Q: Is it easy to build a DIY NFT hydroponic system?

A: Yes, a DIY NFT hydroponic system is relatively easy to build, even for beginners. This article provides step-by-step instructions on how to construct and set up your NFT system.

Q: How often should I check the nutrient solution in a DIY NFT hydroponic system?

A: It is recommended to check the nutrient solution in a DIY NFT hydroponic system regularly, ideally a couple of times per week. This ensures that the solution is at the proper pH level and contains the necessary nutrients for the plants. When the plants get larger and uptake increases, your frequency of checking will need to increase also.

Q: Can I grow any type of plant using a DIY NFT hydroponic system?

A: We would say ‘most’ types, but not all types of plants. You can certainly grow a wide variety of plants using a DIY NFT hydroponic system. Leafy greens like lettuce, herbs, and even some fruiting plants like tomatoes can be successfully grown in this system.

Q: What are the advantages of using a DIY NFT hydroponic system?

A: Using a DIY NFT hydroponic system has several advantages, including faster plant growth, higher yields, and water efficiency. The plants have access to a constant supply of nutrients, which allows them to grow quicker and produce fuller plants. Importantly, the system uses less water compared to traditional soil gardening as it recirculates and conserves water.