What is a DWC system?
The DWC (Deep Water Culture) or Deep Water Culture system is an active hydroponic system where the roots are suspended and immersed directly above and in the nutrient solution. The use of an air pump and bubblers makes it possible to aerate this nutrient solution.
This not only serves to aerate the nutrient solution but also allows it to be constantly in motion and thus to avoid the formation of algae and fungi. To test this system yourself, it’s here .
How does a DWC system work?
The DWC system consists of the same way as the Kratky method system, a tank with lid. The plant is then placed in a hydroponic basket, placed in the lid. Then the tank is filled with a suitable nutrient solution. At the beginning it is important that the level of the solution is high enough to prevent the plant from drying out. We fill at least up to the hydroponic basket.
Unlike the Kratky method , in this system, an air pump with bubblers is placed directly in the nutrient solution. The latter form bubbles which burst into small droplets on the surface of the nutrient solution, thus splashing the root mass. This creates a perfect moist environment for root oxygenation.
The DWC system is also an active non-circulating hydroponic system. Indeed, the nutrient solution does not circulate between different culture chambers but remains in motion in the reservoir which is the culture chamber.
What are the advantages of the DWC system?
In a DWC system, the roots can more easily and quickly pick up the oxygen and nutrients present because they are immersed in the nutrient solution. Plants therefore do not exhaust themselves searching for nutrients that are readily available. In short, they have a dazzling growth and therefore an incredible production.
Then, just like in an NFT system , there is no substrate, but on the other hand, the DWC culture chamber also acts as a reservoir and is therefore much larger. It is therefore possible to grow plants with larger root systems such as fruits and vegetables such as peppers, tomatoes, eggplant, zucchini or peppers.
In addition, this system is simple to manufacture and use. There is no watering cycle unlike the tide table . It is therefore not necessary to program a timer to define a watering cycle.
What are the disadvantages of the DWC system?
The DWC system is based on active hydroponics which requires the use of electricity. In the event of a power outage, the nutrient solution is no longer aerated, which can kill some of your plant’s roots. On the other hand, if they are still in contact with the nutrient solution, its development is reduced but the plant does not dry out.
In addition, the DWC system being closed circuit and non-circulating, there are strong fluctuations in the nutrient solution. It must therefore be checked regularly to ensure that the EC and pH values are correct. These fluctuations will depend on two things: the type of plant grown and the capacity of the reservoir. Generally, a stable solution can be promoted by matching the size of the reservoir to the plant being grown. Indeed, the more a plant is greedy, the more the reservoir must be important. A large reservoir therefore makes it possible to limit the frequency of checking the nutrient solution, but necessarily takes up more space.
Some recirculating systems exist and are commonly referred to as RDWC. They use an external tank to circulate the nutrient solution in the different culture chambers. This makes it possible to obtain a homogeneous solution. For a beginner, these systems are a little more complex to manage than the traditional DWC and they are much more expensive. To be reserved rather for those who have already had a first successful experience with hydroponics.
What types of plants can you grow with a DWC system?
We have seen that it is possible to grow vegetable plants that produce fruit. You should know that these plants are very greedy in nutrients. It therefore becomes important to check the parameters of the nutrient solution regularly as we have seen above. To overcome this problem, it is essential to use a large tank. We noticed that with a 10 L DWC system, it was necessary to check the nutrient solution very regularly, a stalk of tomatoes could drink up to 5 L per day. We therefore recommend using a tank of at least 30 L to benefit from more autonomy during this type of more demanding crop.
It is also possible to grow leafy vegetables, but there are systems offering much better yields for the same cultivated area, such as NFT. Otherwise you can adapt your system to accommodate several plants. In this case, a DWC system with a 30 L reservoir could accommodate up to 6 feet of leafy greens.
Finally, with a DWC system that has a smaller tank, between 5 and 10 L, you can try growing aromatics. It’s very easy, to know how to do it, see our article: ” Growing basil in hydroponics “.