Growing cannabis using NFT is a very simple and highly effective method of achieving massive yields and is one of my personal favorite hydroponic systems to use. There are many benefits associated with the nutrient film technique, so in this article, I break down all you need to know, from the pros and cons, mistakes to avoid, and my top tips for using this hydroponic method.
What is NFT, and How Does it Work?
Nutrient film technique is a method of growing cannabis that uses a water pump, reservoir, and table/water pipes. A recirculating system, which requires the water pump to operate 24 hours a day, produces a slow stream of nutrient solution with which the plant roots are in permanent contact.
Description of how an NFT Table System works
Rockwool cubes or a suspension method with net pots facilitate this process. As the plant’s roots have access to a free-flowing nutrient solution, their growing ability is not restricted. This is why they are popular in commercial-scale farming and well known for their huge yields.
Difference between Rockwool and Netpot growing
An NFT hydroponics system works with angled tables (a 15-20 degree decline). It is a similar design to recirculating dripper systems. The nutrient solution will enter via the pump from the top of the table and is recirculated back, causing a cycle that ensures a consistent flow of moving water.
NFT systems can come in all shapes and sizes, with two distinctive designs. One uses a flat table, and the other uses plastic drain pipes. You will often see this design incorporated in large-scale lettuce production.
A setup of an NFT system using a drain pipe
The Pros and Cons of Using an NFT Method for Cannabis Hydroponics
As a big fan of the simplicity behind the nutrient film technique system, I have learned some of its positives and negatives. Below are a few pros and cons I discovered over the years.
The Pros
The root mass of cannabis plants can become enormous and thick.
You can reduce the vegetative time to 7–10 days to avoid oversized plants.
The pumps run 24/7, so no hand watering or much maintenance is needed.
NFT tables are excellent for small spaces and stealth grow boxes.
Creates an easy-to-use system that’s recommended for beginner growers.
Reservoir changes are straightforward and simple to perform.
Building your own version is cost-effective and won’t break the bank.
You can have some of the biggest yields ever using NFT systems. (I have.)
The Cons
Maintaining the correct water temperature can be difficult
Algae can grow on the surface of the rockwool cubes.
Some systems can require up to 50+ liters of nutrient solution.
Allowing plants to grow too big during an 18/6 light cycle is often an issue.
Water pumps can malfunction or begin to lose efficacy over time.
How to Set Up an NFT Grow for Cannabis
Due to the versatility of nutrient film technique systems, there are many possible designs. You can choose from the large yielding table design using rockwool to the drain pipe model popular in commercial lettuce production and vertical farming. For more on your options, I have created a dedicated separate article explaining all you need to know about how to set up and maintain an NFT hydroponic system and what to consider.
Example of NFT Advanced drain pipe system set up
Example of a setup of an NFT Advanced Table system
How Does NFT Differ from Other Hydroponic Methods?
As a huge advocate for indoor hydroponics, I have enjoyed trying all sorts of systems, including building my own all-inclusive designs, allowing me to change from top dripper to NFT to aquaponics or aquaponics.
That being said, I still find NFT systems the most user-friendly, and the ‘plug-and-play style works perfectly for my needs. With NFT designs, no noisy air pump or soundproofing is needed, and very little electricity is used.
Are you ready to give it a try? Below are some factors to consider if you are considering jumping from organic methods to nutrient film technique.
Skill level:
This is the ideal entry-level system for a first-time grower or one with little experience. You will need to get your head around pH and E.C. first; however, it is nothing too complicated!
Maintenance level:
Apart from making fresh nutrients and frequent reservoir changes, less maintenance is required than DWC and RDWC. It is only later, during the flowering stage, that you may need to change the reservoir more often.
Practicality value:
NFT systems are incredible for producing big yields in small spaces. For growers limited to a small plant count, look no further than the NFT system.
Overall expenses:
A complete NFT system that’s ready to plug in and start your career as a hydro grower will only cost you around $70 for a basic 40 cm x 60cm size. Large table systems range closer to the $250 mark. Hydroponics can become expensive, especially when using 4-8 part nutrients.
Noise factor:
If you are not a fan of running noisy air pumps and DWC systems, why not consider the peaceful and tranquil sound of dripping water and the mild buzz of a water pump? The noise levels are minimal once the pump is on, creating a silent and stealthy grow room.
Mistakes to Avoid While Using NFT Systems
Don’t be lazy and forget to change the reservoir. The plants must regularly receive fresh nutrient solution once they start drinking heavily.
Avoid running out of nutrients at any stage of the grow cycle, and make sure you have more than enough to last you. Nothing is worse than running low on nutrients and, for whatever reason, being unable to replace them.
Algae can form on the top of rockwool cubes and become dark green with a slimy consistency. Do not let algae begin to develop. I always like using cube caps as an extra preventative.
Not correctly calculating your floor plan and adding too many plants in a small space. This will result in severe overcrowding in your garden and, in some cases, the removal of 1 or 2 plants later down the line.
Allowing the reservoir tank to sit on cold floors causes the nutrient solution to dip below the preferred 64.4 degrees Fahrenheit (18 ℃). Avoid doing this.
My Top Tips for Using Nutrient Film Technique
Top tip #1:
Cube caps are small plastic covers that are designed to sit over the top of the rockwool cube. Consider making your own if you cannot buy these from the grow shop. As long as they serve as a cover from the light to prevent algae, you will be fine.
Top tip #2:
Always keep a digital pen in your grow room to check the pH and E.C. of the current nutrient solution. How much the water level drops each day will also indicate how fast the plants are drinking the nutrients.
Top tip #3:
If you are making your own NFT system with pipes, consider this fact: the bigger the pipes installed, the bigger the plants will be. Many growers using homemade systems have great success with a high volume of smaller-sized plants reaching 60-75 cm tall.
My Final Thoughts on NFT Systems
I first encountered an NFT tray at a friend’s house. Growing inside a converted wardrobe with a 400w HPS lamp and reflector, I could not believe the size of the plants he was flowering. For a first-timer, he was hitting over 9 ounces per plant dry and told me how he could be at work and not worry about a watering schedule.
Almost 20 years later, I am writing this article and still recommend silent NFT systems. They produce an ambient dripping sound, allowing the bedroom grower to sleep in the same room without noisy pumps or vibrating floorboards.
I would suggest learning the ropes with NFT systems, then giving DWC, flood and drain, and aeroponics a try later down the line. I feel that every grower will find the perfect system for them based on skill and experience, practicality, and maintenance levels. Good luck finding out which system works best for you and your indoor growing needs, and be sure to check out Robert Bergman’s Grow Bible to take your growing knowledge to the next level!
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