what is nft?
NFT stands for ‘nutrient film technique’ and is one of the most popular types of hydroponic gardening systems. NFT systems require a reservoir of water, in which a pump will transport the water upwards via plastic tubes to containers holding your plants. The grow tube containing the plants is at a slight angle, so gravity will help to take the water back down into the reservoir. The water runs back down into the reservoir and is pumped back up again into the plants, in a continual flow.
The word ‘film’ is used to describe the thin, small layer of water that will be running over the roots of the plant at one time. The bottom of the roots will receive a small amount of water, while the top half will be left dry and able to take in the oxygen from the air.
benefits of an nft system
- NFT systems use much less water and nutrient consumption
- They are low maintenance and easy to clean
- The grow tubes can easily be expanded if needed
- It’s an affordable option, which can be set up with DIY supplies
- The system is easy to clean
- It’s easy to check the healthiness of the plant’s roots
- NFT systems can produce high yields
- A small system is great for growing indoors, in a relatively small space
- You can control the exact amount of nutrients your cannabis plant needs, increasing plant quality
- Reduced chances for pests
- It’s environmentally friendly
disadvantages of nft systems
As with all growing systems, there will always be some disadvantages. With the NFT system, it can be a little complex to set up initially. This can put some beginner growers off, as they opt for the more familiar soil growing.
Also, if you encounter a problem with your equipment, such as a broken water pump, this can quickly ruin all of your plants, if gone unnoticed. This of course can be overcome by regularly checking your pumps and equipment. The NFT system is not good for plants and vegetables with large or complicated root systems.
what do you need for an nft system?
This is the tank that holds the water. It’s important you find a good quality reservoir and make sure to check which plastics are safe for your system (HDPE, LDPE and PP are all safe for the garden). A simple storage container can work well for DIY growers.
These are the tubes that your plants will be placed in. This is where you can get creative, with many growers opting to make their own grow tubes from PCV tubes. These are easy to cut holes into and can be bought easily. Net pots or containers are used to hold the plants within the grow tube.
The only downside to PCV tubes is that because they are round, the water may not run through the plant roots evenly, potentially causing your plants not to grow as well. Another option is rain gutters or a tray with a flat bottom, or better yet, specific tubes that have been designed for NFT systems.
The grow tube or tray is placed at an angle, to let the water slowly run through the roots at a low speed. The flow rate is generally best at 1 litre per minute (although can be 0.5 to 2 litres per minute without too much of a change in nutrient balance).
To work out the right angle, use a 1:30 ratio. Meaning, for every 30 centimetres of your grow tube length, there should be a 1cm vertical drop.
The great thing about NFT systems is that you do not need a super powerful pump (for smaller systems). Obviously if you have your tubes extended upwards on more levels, you will need to slightly bigger pump.
To work our what size pump you will need, you will have to measure the length from the bottom of the reservoir to the top of your highest grow tube (add a little extra as a buffer). You will then need to check the head height of the pump you wish to buy. A pump with a 4ft head height will pump to around 4 ft. As the system only requires water to run through at a low rate, try and choose a pump with the lowest gallons per hour (GPH), but which reaches the highest grow tube on your system.
Try and opt for black or dark coloured tubing, as the lighter colours can often attract algae. The tubing should be long enough to fit from the length of your water pump to the highest grow tube in your system.
The air pump will pump oxygen into the water in the reservoir. These may not always be necessary in NFT systems but it’s always a good ides to give your plants as much oxygen as they need.
Air stones increase the circulation of oxygen in the water by making tiny oxygen bubbles that spread around the water in the tank. These oxygen bubbles are then pushed through the water using the air pump.
You will need some basic net pots, which are the baskets that hold your plant.
You will need to start your seedlings in a growing medium, such as coco coir, perlite, clay pellets, starter plugs or oasis cubes. These growing mediums help to support the plant roots and provide a good oxygen and water balance.
Hydroponic Nutrient Solution
Good nutrients produce quality plants and are essential to getting a good yield. Nitrogen, Phosphorous and Potassium (NPK) are the most important nutrients for all plants.
Cannabis plants require different levels of nutrients during the growth cycles. During the vegetative stage, your plant will need lots of potassium and nitrogen and medium to high amounts of phosphorous. In the flowering stage you will need lots of potassium and phosphorous and low amounts of nitrogen. It is best to choose nutrients specifically made for hydroponics.
tips for using an nft growing system
Try testing out your system before you put your plants in. Make sure it is thoroughly cleaned, your equipment is working properly and that the water is at the correct flow rate. Checking first lowers the chance of your plants getting ruined.
Regularly check your system
Make sure to regularly check the nutrients, PH levels and whether your equipment is all in working order. If one of these is not working properly, then it can destroy your plants.
Changing the reservoir
You should aim to change the water and nutrient solution in the reservoir around every 10 days. After pouring in fresh water, allow it to sit for around 24 hours, to allow the chlorine to disappear. Then add the nutrients.
Make sure you start your plants off in a growing medium before putting into the system. The roots should be well established before you transfer them to the grow tube.
Keep it clean
Be sure to keep your reservoir and tubing clean after each grow cycle. This can be easily done with NFT systems.
The pH level should be maintained regularly at around 5.8 and 6.2.
Using a sponge or elevating your water pump can reduce the vibrating noise.
Keep nutrient solution at about 18 to 21 degrees Celsius.