What is a Deep Water Culture System?
Deep water culture is a hydroponic farming technique where plant roots are submerged in the nutrient and oxygen-rich water solution at all times. This system is the most popular hydroponic system for beginners and classroom instructional purposes due to its technical simplicity.
DWC hydroponic farming system consists of plants whose roots extend from a net pot that is suspended from a lid with the roots hanging into the nutrient solution in the reservoir container. An air pump and airstone are used to aerate the nutrient solution.
The diffused oxygen allows your plant roots to take up maximum amounts of nutrients resulting in accelerated growth. The accelerated oxygenation of the roots improves water nutrient absorption which leads to accelerated cell growth. Efficient nutrient absorption leads to reduced amounts of growth fertilizers used compared to other systems.
It is called deep water culture mainly because of two reasons, one is because of the deep nutrient reservoir which stores a large amount of nutrient rich water.
The second reason it is called deep water culture is because of how much root is submerged in the nutrient rich water. The roots are going to stay in water on a 24hrs basis.
The DWC system is a fairly simple and straightforward design. This type of hydroponic farming system can be built with readily available equipment available online or at your local hardware store. It’s also an inexpensive to build and operate.
Featured Deep Water Culture System
What Plants Grow Best in a Deep Water Culture System?
The system is usually suitable for growing greens such as lettuce and other long-term crops such as,
- Tomatoes with proper support
- Collard greens
- Bok Choy
Pros of Deep Water Culture.
- Boosted Growth due to nutrient water and oxygen.
- Better cell growth of the plant.
- Lower consumption of fertilizer.
- Easy and most efficient way of hydroponic farming.
- Easy to maintain.
- Mobile method.
- Fast growing time.
Quick Setup Guide on Deep Water Culture (DWC)
To set up a deep water culture hydroponics system, you will need the following materials;
- Plastic Grow Cups/ Net Cups
- Grow Media/Medium
- Air Pump & Tubing
- Air Stones
- Hydroponic Nutrients
- Thermometer and ph testing kit
All of the materials used in this build are available on amazon. Below I’ve provided links to the specific materials I used to build my system. For a more simple startup I’ve also included a link to a ready to go system, just add plants and sunshine. We are now going to focus on each step.
- Reservoir– The Reservoir used for Deep Water Culture should be food grade so they don’t release harmful toxins into the water under UV light and high heat. They also have some other properties which are suited for this particular growing technique. The reservoir should not be transparent and also be algae resistant. The reservoir should also be big enough (minimum 5 gallon bucket) for storing enough of the nutrient rich water. If you are doing this for your own interests or as a hobby you may buy a single bucket or small reservoir. Otherwise a 4 – 8 bucket system or larger reservoir is recommended for a new setup.
Plastic Grow Cups/ Net Cups– These cups hold the plants on the floating platform. It’s recommended to use tapered cups with a wide rim to prevent them from falling into the solution. The net cups or the grow cups should be UV resistant and highly durable for the better growth.
Growing Media or Medium– Growing mediums that can be used include rock wool, vermiculite, perlite or clay pellets. In addition to supporting the young and delicate roots and stems, the medium performs wicking functions during early plant development to move nutrients to the higher parts of the roots.
Air Pump and Tubing– An air pump is extremely critical and important to the DWC system because the nutrient solution is stagnant and needs constant aeration to add oxygen and prevent the plants from suffocating. In the DWC system, the air pump works 24/7 and a power outage may cause detrimental effects on your crops. Aeration of the water leads to proper bubbling in the reservoir which promotes an even mix up of nutrients and oxygen to the roots.
Air Line/Tubing– This creates the connection between the external air pump and the submerged air stone. The size and length of the tubing depends on the pump size and the distance from the pump to the air stone respectively.
Air Stones- This is a highly porous air diffuser that is submerged into the nutrient solution which evenly diffuses air into the solution for plant uptake. Air stones are available in all aquarium stores and the size depends on the size of your system and the size of the air pump.
Hydroponics Nutrients- These are trace elements, fertilisers, and other growth supplements that are essential for healthy plant development. These may either be the commercial premixed hydroponic fertilisers or homemade organic fertilisers.
Thermometer and pH Testing Kit- These are important in maintaining the best environment for optimal plant growth. Since the nutrient solution is covered, the solution temperature tends to rise while ph varies widely. Water temperature and ph are essential factors in proper plant growth.
Lighting– If you intend to set up your deep water culture hydroponic system indoors, it’s essential that you consider proper lighting for good plant growth. Garden system size and the plant growth phase determine how many light fixtures and what wattage is needed. The common types of lighting used in commercial setups include high-intensity discharge (HID) lamps during the growth phase and high-pressure sodium (HPS) during bloom to maximize yields. Multi-spectrum LED grow lights perform well in a small home system.
How to Build a Simple Deep Water Culture System
Tools required in preparing the hydroponic deep water culture (DWC) setup include sharp cutting tools, tape measures, and a marker.
- Using a tape measure, measure the dimensions of the reservoir. Using the measurements, cut a piece of floater Styrofoam a quarter-inch smaller than the reservoir’s dimensions; this is to allow the floater to move up and down with the changing solution level.
- Place the grower cups on the foam, using a pencil, trace the bottom of the pots on the Styrofoam. Using a sharp knife, cut out the holes on the Styrofoam. Ensure that the grower cups hang just below the Styrofoam but don’t fall through.
- On one edge of the Styrofoam cut out a hole for the airline.
- Add water to the reservoir and mix the nutrient solution as per the instructions by the fertilizer manufacturer. Check the ph of the solution and adjust accordingly. It’s important to note that ph requirements vary from one crop to another.
- Attach the airline from the air pump to the air stone and then place the air stone at the bottom of the nutrient reservoir. Switch on the pump to make sure the air stone is releasing air bubbles.
- Add the growing medium of your choice along with one plant into each cup. The medium should not fall through the holes in the cup.
- Place the floater Styrofoam on the surface of the nutrient solution. Place the grow cups to their designated holes on the Styrofoam platform.
Pro tips for maintenance of Deep Water Culture
- Regularly monitor the root growth. Once the root system is long and robust lower the solution level to prevent overfeeding.
- Monitor the temperature. The recommended nutrition solution temperature is 62-68 oF (17-21oC). Too much heat reduces dissolved oxygen in the solution while low temperatures lower the plant’s metabolism.
- Monitor dissolved oxygen level. You can monitor dissolved oxygen using an oxygen meter.
- Checking the pH regularly helps in controlling growth in the various growth stages. For example, a pH of 6.0-6.3 is for vegetative growth while 5.7-5.9 is optimal for flowering and fruiting.
- Check the nutrient solution regularly to prevent starving off the plants topping up when needed. It is recommended to refill with pure water during the first refill to prevent nutrient build-up. During the second refill, the reservoir is drained and then refilled with fresh solution.
Enjoy this video on how to set up a deep water culture system –