Deep Water Culture (DWC) is one of the most popular hydroponics techniques. It is also hydroponics in its purest form as it sticks completely to the principles of hydroponics.
This system is also one of the easiest to set up. It is very effective and efficient in terms of water usage and nutrient absorption. In this article, we are going to explore the concepts of the technique and how hobbyists and commercial growers can get started.
What is Deep Water Culture (DWC)?
DWC – Deep Water culture or Direct Water Culture is a variation of the hydroponic system where plants are grown in a water-based nutrient solution, well-oxygenated to ensure proper plant growth.
The word “deep”, references the fact that the roots are submerged deep in the water. The reservoir of the system usually contains a good amount of water that ensures the stability of the nutrient solution. This also reduces the amount of time spent on maintenance and monitoring.
How does DWC Hydroponics Work?
In DWC, the plants sit directly in the water that has been added with nutrients for them to absorb. The water is provided with oxygen by the use of an air pump. This helps them to get fast growth, and could also help them grow more than their soil-grown counterparts.
The air pump and airstone attached would run 24 hours as the plants’ roots are submerged in the water 24 hours a day. This prevents the plant roots from being waterlogged or running out of oxygen.
The plants are placed in net pots and placed above the nutrient solution in the reservoir. The net pot features several holes that allow the roots of the plant to spread in different areas as they go. This is better than having a regular pot with only a single hole.
Advantages and Disadvantages of Using Deep Water Culture System
The DWC system offers the following benefits over other systems:
- It is one of the simplest to use and set up. With the DWC system, getting the material for the system is rather easy. You can actually improvise on the materials and get the system running successfully.
- This system offers flexibility as it can be set up indoors or outdoors.
- There is less chance of pests or diseases affecting the plant.
- Since the plants are submerged in nutrient-rich water, you can save up on nutrients and prevent nutrient waste. In addition, you won’t have to worry about nutrient deficiency.
- When set up correctly, this system is effortless to maintain. It also requires very little time and attention from you!
- The nutrient solution is virtually still which could lead to bacterial growth, algae growth, and fungi and molds. These could cause water-borne diseases to break out and cause damage to the plants.
- The pH of the nutrient-rich water can also fluctuate wildly and would have to be monitored regularly.
- Not all plants can stand having their roots wet 24/7 and could begin to rot if used in this system.
Variations of Deep Water Culture
Aside from the traditional Deep Water Culture we have just talked about, there are several varieties to this system type.
The bubbleponics is similar to the DWC in the sense that it features the same set-up, and equipment. It includes the reservoir, air pump, airstone, and all other features.
The main difference is the inclusion of a water pump inside of the reservoir. The function of the water pump is to move the nutrient solutions to the top of net cups that hold the plants and then fall back to the reservoir. The bubbleponics system acts as a top-feeding DWC and a recirculating system.
Bubbleponics tends to be very effective at the beginning phase of the plants’ growth, when the roots are still short, and cannot fully reach the water below. Through this system, you can provide the nutrients and water for the roots to grow faster and until when they can sink deep into the reservoir’s nutrient solution.
The Kratky method
The Kratky Method is the Deep Water Culture, but it without the inclusion a pump. This method is a passive system that doesn’t require any electricity.
Using the Kratky method, there is usually an air gap between the roots and the surface of the nutrient solutions. This leaves some parts of the roots submerged in the water while the other parts are exposed to the air. This system is one of the most cost-effective hydroponics methods to start.
Re-circulating Deep Water Culture (RDWC)
The downsides of the traditional DWC make it difficult to scale big. With recirculating deep water culture, these downsides are solved and the system can be used by commercial growers.
Re-circulating DWC works like a flood and drain system, but the nutrient solution are never really drained out of the system.
The biggest advantage of this system is the fact that you can scale big as the only requirement is to add water, oxygenate, and calibrate the central reservoir. The water and nutrients that feed the plants can be reused or re-circulated from one bucket to another.
Which Plants Can Grow in DWC?
There is a wide range of plants that work best in the deep-water culture system. In general, the best plants that grow well in a DWC system are anything that doesn’t have to flower. Taking a look at the available plants, you have a wide range of lettuce varieties.
In addition, there are also many herbs and vegetables like tomatoes and peppers that will grow well in such conditions. Even fruits like squash will grow in DWC, though with these options you will have to apply more effort and higher maintenance to get results.
Research has shown that plants grow a lot better in DWC than in regular soil. They don’t just grow faster and bigger but also provide a higher yield. Overall, there are lots of benefits to using this system over the traditional system but that’s only if it is done right.