A cultivation method that does not use soil, but rather keeps the roots of the plant submerged in water. Growing media such as coco coir, clay pebbles, or another lightweight, expandable aggregate are used with liquid nutrients to replace soil. Hydroponic cannabis gardens are considered more efficient than traditional soil-based gardens, as the open-root system allows for direct uptake of nutrients and oxygen.
He wanted to grow plants year round, so he decided indoor growing using hydroponics was the right cultivation method for his cannabis business.
There are multiple methods of hydroponics — the best one for you will depend on your budget and level of experience.
More about Hydroponics
Hydroponics is used to describe this particular cultivation method, which uses water instead of soil as the primary source for growing cannabis.
The use of hydroponics is believed to date back to 600 BC, where the cultivation method was used in the Hanging Gardens of Babylon. Hydroponics was also used in the 10th and 11th centuries by the Aztecs to grow crops at Lake Texcoco, and references to hydroponics were found in the writings of Marco Polo following his exploration of China in the late 13th century.
Hydroponics is widely considered to be a more effective cultivation method than soil-based gardens because it allows water and other nutrients to be applied directly to the root — as opposed to soil-based gardens, where water and nutrients are absorbed through the soil. This allows the root to access the nutrients it needs for optimum growing without having to “search” through the soil—which, when done correctly, can result in larger, healthier plants.
Common Hydroponic Techniques
While there are many systems that fall under the hydroponics umbrella, since it encompasses anything that’s soilless and provides oxygen, water, and nutrients to growing cannabis plants, some of the more popular techniques include:
Deep Water Culture
Arguably the most simple of all hydroponics systems, the deep water culture technique is popular with beginners just starting out with hydroponics or cultivators looking to keep costs low.
In this technique, each plant is placed in a separate pot or container. The pots and/or containers are then placed in a tray submerged in water. If the pots or containers have the ability to hold water individually, the tray is unnecessary.
Nutrients are added to the water, which is kept oxygenated using air pumps, allowing the roots to remain submerged underneath the water.
The wick system is another hydroponics technique favored by beginners due to its simplicity. With the wick system, plants are placed into a container over a reservoir containing nutrient-filled oxygenated water. One end of the wick, which could be constructed from any absorbent material like cotton or cloth, is placed in the reservoir while the other end of the wick is placed in the container. The wick acts as the delivery system, using capillary action to draw up nutrients and water to “feed” plants.
Nutrient Film Technique
Similar to deep water culture, with the nutrient film technique, the roots of the cannabis plant are continuously submerged under water. However, nutrient film technique-grown, plants are placed in a “planting tube”(typically constructed from PVC piping). The oxygenated water containing the nutrients is pumped from a reservoir into the tube. The tube is placed at an angle, allowing the water to flow through the tube and soak the roots of the plant before draining back into the reservoir.
Drip systems are popular with commercial growers because it allows for better control of the amount and frequency of nutrient solution delivered to each plant. With a drip system, each plant has its own individual water jet through which the nutrient solution is delivered through a time-controlled pump. Any excess solution is then collected back into the reservoir through the recovery system.
Ebb and Flow/Flood and Drain
The ebb and flow, also known as flood and drain, system is unlike other systems in that it doesn’t keep the roots of the plants constantly submerged in water. Instead, the grow tray is flooded with the nutrient solution. After the flooding, the nutrient solution is then drained back into the reservoir, exposing the plants to oxygen before repeating the process again.
Materials Needed for Hydroponic Growing
While the materials will vary based on hydroponics system, there a few materials necessary for all hydroponic grow operations, including:
- Seeds or clones
- Containers for the plants
- Potting medium (such as clay pebbles or coco coir)
- Grow lights
- Water pump
- Aquarium air pump
Ideal pH Levels for Hydroponics Nutrient Solution
One of the largest contributing factors to a successful hydroponic grow operation is the pH level of the nutrient-filled oxygenated water solution. In order for healthy plants, the pH of the solution should be kept slightly acidic, between 5.5 and 6.5 pH. The exact pH level will differ depending on the stage of growth. There are a number of products on the market to help growers accurately measure pH levels.