Aquaponics has changed the farm to fish feeding the plants without soil.
That is right, A farmer just needs fish, good bacteria (both of which live in the aquaponics tank) and the plants will produce yields.
There are three types of aquaponics systems:
- Media-based aquaponics
- Nutrient film technique (NFT)
- Deep water culture (DWC)
In this post, we are going to compare :NFT and DWC, advantages, disadvantages, and which is better overall.
What Is an NFT Aquaponics System?
The NFT system consists of growing plants on horizontal pipes and provides nutrients through a shallow, slow-moving stream of nutrient-rich water.
The pipes, which are generally made of PVC, have holes/openings on top to hold the seedlings in place so that they can establish their roots in the water and allow the shoot to grow out of the pipe.
An NFT system encompasses the following components:
- fish tank
- pump
- mechanical and bio filter
- growth pipes
You put fish into the tank and feed them, and they are cycling nutrients when they eliminate waste in the tank.
The pump moves the waste-rich water through the mechanical filter to remove food remnants and debris and then flows into a bio-filter.
In the bio-filter, the nitrifying bacteria will convert the fish waste into nitrates and other nutrients suitable for the plants.
The waste-rich water then flows through the growth pipes in a shallow film and serves to nourish the plants and increase their growth.
Keep in mind: The net pots and growth mediums, like clay and pebbles, hold the plants in place inside the holes and prevent them from being dislodged by the flow of water.
NFT Aquaponics System Pros and Cons
The NFT method has both benefits and drawbacks, which should influence your decision to choose or forgo the method.
Pros
- The roots of the NFT system have a good supply of air because the pipes are sized properly, therefore air will flow freely through the holes in the grow pipe.
- The holes in the pipes make it easy to inspect or detect any signs of disease to the root system.
- Water flows out of the grow pipe continually, which flushes away any solids that collect in or near roots, which allows the roots to absorb the nutrients in the water without obstruction.
- The flowing water dampens the growth of fungal pathogens that cause diseases to plant.
- And finally, this system does not use a lot of water.
Cons
- NFT is limited to smaller types of plants. You cannot grow larger plants with a lot of roots.
- A power outage or pump failure can ruin the process if the water does not flow.
- Root clogging is a big issue in the NFT system, especially if you do not choose the right size/diameter of grow pipes.
- Starting an NFT system is costly.
- The shallow film of water flowing through the grow pipes cools down or heats up quickly, making temperature management difficult in this system.
What Is a DWC Aquaponics System?
The DWC system is also known as the raft system of aquaponics.
It is a floating aquaponicowobich allows you to float the plant while it’s roots floats on the water with fish and nutrient good bacteria.
The rafts are made from polystyren or foam board with holes ontop of the raft in which the plants can get the nutrition and grow!
The DWC system includes:
- fish tank
- grow canals
- floating rafts
- pump
- bio filter
- mechanical filter
- aeration equipment
The fish live and grow in the water tank, and them, the fish waste is released back into the water.
The water is pumped through the bio-filters and mechanical filters into the grow canals.
Inside the grow canals, the hanging roots take nutrients and oxygen.
The DWC is not well-aerated so aeration equipment will be used to add oxygenated air.
Finally, the water is recycled back into the fish tank- circular economy!
DWC Aquaponics System Pros and Cons
DWC is one of the widely-used aquaponics systems, but it has its benefits and drawbacks.
Pros
- Setting up Deep Water Culture (DWC) is simple and cheap, which is helpful for amateurs.
- DWC supports a high rate of plant productivity due to ample space, nutrients, and oxygen.
- Water in DWC flows in bulk, which is helpful in maintaining temperature.
- DWC supports relatively larger plants as a result of the ample growing space and freely hanging roots.
- The raft system allows DWC to be reused after a harvest, so DWC is well suited for larger commercial operations.
- Easy to clean and maintain.
Cons
- The high water volumes and large footprint can create breeding grounds for mosquitoes and require continual abatement methods.
- The floating rafts inhibit air movement in the water, so aeration methods need to be introduced to provide oxygen to the water and prevent root rot.
- It is not feasible to rear herbivorous fish in a DWC system because they will consume the free-hanging roots.
Nft Vs Dwc Aquaponics: Which Is Better?
The ongoing discussion between nft and dwc aquaponics has lasted as long as hobbyist and commercial aquaponic farming has begun – both having unique advantages and disadvantages.
The deep water culture method is more popular than the nutrient film technique since DWC is more simple and has a higher productivity rate.
In commercial culture situations in which the farming is being done for a profit, setting NFT system up is not worth it in the end.
Deep water culture also requires little to no maintenance, while NFT requires constant checking, power back up, pump maintenance, etc.
Nutrient deficiency is among the biggest problems for aquaponics as well. In the NFT system, the shallow film of water nourishing the plants leaves them more vulnerable to nutrient deficiency.
On the other hand, standard deep water culture has an essentially limitless amount of nutrients flowing in the nutrient rich water.
This gives even another reason as to why DWC is preferred in a large aquaponics project rather than NFT.
Final Verdict
Both NFT and DWC are aquaponic systems that help to improve food security and sustainable agriculture.
They both have their pros and cons, and it depends on you and your growing goals and budget and preferences.
But, if we had to take a stand, we would have to say that the deep water culture system (DWC) is better on so many counts than the NFT.
It’s easy to set up, beginner friendly, cost-effective and does not require a lot of monitoring.
Also, you can grow a larger variety of plants on this system than under NFT, where you are limited to small, non-fibrous rooting plants.
So, whether you want medium-sized vegetables, flowers or fruits, DWC will serve you for both domestic and commercial aquaponics.