How To Setup a Hydroponic DWC Deep Water Culture System?

What Is DWC Hydroponics
Now that you know the products that best suit hydroponics growing, it is good to understand further, what DWC is and what it entails especially for those trying hydroponics for the first time or those that are thinking of venturing into the system. In DWC HYDROPONICS SYSTEM, plant roots grow suspended in an oxygenated in a rich nutrient and water solution. The three sections of the solution, water, oxygen and nutrients provide the weed crop with everything they need for healthy growth. Oxygen plays a big role in making sure the roots get the oxygen they need from the water spaces, as there is no soil in the solution. With the oxygen, the crops would drown in the water. To make sure that the water has enough oxygen always, an air stone and pump are used.
Water, which is the main hydroponic farming system, means that you will not need to water your crops. Water acts as the soil in this case. Nutrients are necessary for the growth and health of any crop. Good quality soil contains all the right nutrients that foster proper and strong growth for the crops. In hydroponics, no soil is present but the water needs the nutrients in order for the crops to grow. In this case, the water is fed with nutrients that boost and nourish the weed crop.
DIY Hydroponic Deep Water Culture
A DIY hydroponic DWC is very easy to design. All you need is a 3 ½ gallon bucket, 10-inch net pot, an air pump, air tubing, an air stone, some rockwool, and some expanding clay growing medium or the growing media of your choice. All of this can be found at the local hydroponics or gardening supply store or online. Begin by filling the reservoir (bucket) with hydroponic nutrient solution at a level that is just above the base of the net pot. Connect the air tubing to the air stone and place it in the bucket. Place your plant with visible roots growing out of the rockwool into the reservoir. Surround the plant with either your choice of growing medium or the aforementioned expanded clay pellets. Turn on the air pump. Initially, when the plant is still young, the rockwool needs to be in contact with the nutrient solution so it can wick the nutrients and water up to the plant. As the plant matures, the root system will grow and the level of the nutrient solution can be reduced. Every 1-2 weeks, remove the plant from the bucket and replace and refresh the hydroponic nutrient solution, then place the plant back in the bucket. You can add more buckets to the system, ergo more plants. If you add many buckets, you may need to add or upgrade the air pump.
How to build a DIY hydroponic system:
Before you continue reading about the actual setup of this DIY hydroponic system, watch the video walking you through the process. The rest of the blog post goes into more details about the setup and the exact materials I used for this build.
Seed germination using rockwool
The first stage of creating a DIY hydroponic system is starting seedlings. This means starting seeds in a grow medium. In this case, I used rockwool or stonewool as it’s sometimes called. Rockwool is a growing medium made of basalt melted back into lava and poured into a spinner in a process similar to making cotton candy. It is one of the most commonly used substrates in hydroponic systems across the world due to its inert properties, sterile start, and unique capacity to maintain a great water/air ratio.

Add nutrients and adjust the pH
I started out by adding the nutrients to the water at roughly 1/5 the recommended concentration (an EC of about 200 µm/cm). I use this EC meter to check my electrical conductivity. We can use EC measurements, or TDS measurements to check the concentration of the nutrients.

Finally, adjust the pH to 5.7 (if needed). You will need to purchase a pH up/pH down kit to adjust the pH, and a pH meter, or some pH strips to actually measure the pH.

Soak the rockwool cubes
Immerse the rockwool in the pH balanced nutrient solution until all the rising bubbles are gone. The immersion time depends on the size of the rockwool block, smaller plugs like these only take around 10 seconds. This allows the water to infiltrate the tiny pores in the rockwool and prepare the substrate to be colonized by roots. Let the rockwool drain freely until water is no longer running out of it. DO NOT SQUEEZE. Air will re-enter the larger pores, creating the perfect balance between water retention and aeration.

Add the seeds
I added 2-3 seeds per cube. If several seeds germinate (this is great), simply choose the strongest seedling and clip the others. You can add a single seed per cube, however, most seed companies typically say only 75-80% of seeds will germinate.

diy hydroponic system
Something like a flat skewer will help push the seeds into the small 1.5″ A-OK rockwool plugs. Tear off a small piece from the corner and gently cover the seed hole. This helps maintain a humid environment directly surrounding the seed. I have found this can speed up germination. Pull back these covers around the 48 hour mark so the seedlings aren’t stuck in the plug.

DIY hydroponic system
Place the seeded rockwool cubes in a seed starter tray with a clear covered dome. At this point, heat will do more than light to induce germination. You can purchase heat mats, or set the starter tray in a sunny window (this is what I do). I usually add a very small amount of water to the base of my tray as well, to help create a humid, warm environment.
Build/assemble your DIY hydroponic system
I wanted my grow area to look like a piece of furniture since it would be sitting it the main living area of the house. However, I still wanted it to be functional in case I wanted to control for moisture and humidity down the road. The main growing area is a wire shelving rack, which allows me to adjust the height of my shelves depending on the grow. The wire shelf is surrounded by a custom wood cabinet that I built (not part of this article). Lastly, I attached my lighting to the underside of each wire shelf.
Hydroponic Lighting
By no means will this be an extensive discussion about the different lighting setups available. I am just discussing the lighting setup for my DIY hydroponic system. In this build I chose to go with 36″ LED lights. There are several advantages to using LED lighting, when compared to fluorescent grow light, metal halide, or HPS grow lights.


Advantages of LED lighting:
LED lights produce far less heat than the alternatives. This is crucial when controlling temperature and humidity are important. While some plants will tolerate high heat, others will burn up. LED grow lights can be placed closer to plants in confined areas with very little risk of heat damage.

The LED grow lights of today can rival the light production of alternative sources that use nearly twice the wattage, which adds up to major savings in energy cost. LED’s can come as all-in-one fixtures, which are easier to work with in tight spaces.