Nutrient Film Technique

Thomas Angas by Thomas Angas | Last Updated: April 20, 2020

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When beginners first start learning about hydroponics after maybe reading about it online they usually start thinking about some beautifully laid out system growing row after row of plants – it’s the nutrient film technique that they’re thinking about.
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In this post, we take you through what it is, how it works and how to build your own system before finishing up with a few pros and cons and a rundown of our favourite plants to grow.

Let’s get started!

What is the Nutrient Film Technique?

The Nutrient Film Technique is an active (meaning has moving parts) hydroponics system in which nutrient-rich water is pumped up from a reservoir to a grow tray where the water passes over the plant’s roots before being filtered back down into the reservoir.

The nutrient film technique is very similar to the ebb and flow system as both are active systems and both use a water pump to take water from the reservoir and pump it to the grow table, however, unlike the ebb and flow system which only floods the grow tray a few times a day – the NFT constantly provides your plants with nutrient-packed water.

It’s this easy access to nutrients that make the nutrient film technique an incredibly efficient way to grow plants hydroponically.

How The Technique Works

The nutrient film technique is made up of 2 parts:

The Reservoir

The reservoir is usually a large plastic container or bin like the one shown below and is where store the water for your system, test the pH level and add your hydroponic nutrients.

The Grow Tray

The grow tray is where your pots containing your grow medium and plants are kept (though it’s not uncommon to ditch the grow medium in an NFT system). The tray is angled down so water gathers at the lower end and drain back into the reservoir.

The plant roots dangle down from the net pots into the water and as the nutrients pass over the roots the plant is able to absorb them up through the roots helping the plant grow.

The trick is to allow a third of the plant root to be submerged in the water and the remaining two thirds to remain dry and allowing them to absorb additional oxygen.

Pros & Cons of The Nutrient Film Technique

Like all hydroponics systems, the nutrient film technique has some pros and cons that you should be aware of:

Pros

Low water consumption – NFT systems use very little water. Once you’ve filled your reservoir you’ll only need to top it up every so often making it incredibly efficient. As all the water is kept in the system, you’ll also reduce the risk of contaminating local groundwater supplies.

Easy plant maintenance – As a beginner, one of the things to watch out for is bacteria build up on your plant roots. In an NFT system, it’s incredibly easy to inspect your plants without having to dismantle the system.

Easy hardware maintenance – Again, every so often something won’t quite be working properly – with an NFT system all the parts are easy to access and change out if necessary.

Cons

Very dependent on pump – if your pump fails without you realising then your plants will very quickly dry out.

Roots – in an NFT system your plants roots will grow long! This sometimes causes problems where a large root ball will form and block your channel.

Best Plants To Grow Using The Technique

Generally speaking, any fast-growing plants requiring little additional support grow well within the system, this includes:

If you do want to try to grow something a bit heavier such as tomatoes you’ll need to ensure you provide them with additional support in the form of trellises or garden canes.

The Bottom Line

So there you have it, our guide to the nutrient film technique. While it does take a little setting up it’s a fantastic system for growing plants and provides them with an environment in which they seem to thrive.

Thomas Angas, the founder of Authority Gardening lives with his wife and two darling pups. He spends his free time writing, hiking and learning how to become a better gardener. He launched Authority Gardening in 2017 to help people all over the world their gardens grow.