Dialling in Hydroponic Growing Techniques to Achieve Maximum Yields

Hydroponic gardening is one of the most fun and exciting ways to grow cannabis, whether you’re working with a deep water culture (DWC) setup, applying the nutrient film technique (NFT), or simply growing in soilless growing media like perlite or coco coir. 

Hydro setups boast several advantages, such as using less water and can be easily adjusted to include automation of many basic functions. Whether you’re just starting out or a seasoned veteran of growing cannabis, hydroponics is a sure way to grow some beautiful marijuana plants for yourself.

Of course, there are many challenges and questions that face hydroponics growers: what type of system would be best suited for my needs? How should I maintain my growing space? These questions and more are necessary for hydro growers to take into account, an issue which at first can seem overwhelming. With a bit of research and practice, though, you can achieve higher yields, increase potency and grow beautiful, fruitful cannabis plants. Hydroponic glory is within reach of anyone!

The Most Common Issues

Though the issues which cause you problems in your grow room are uniquely your own and based upon many variables, the fact remains that many growers have experienced similar problems in their own crop production. For this reason, we’ve narrowed down the issues facing hydroponics growers to a few of the most prominent, which will be discussed below.

Picking the Right System

One of the biggest problems growers face when deciding to enter the world of hydroponics is determining just which hydroponic method will work best for their particular needs. There are a wide range of issues to consider when making this decision, such as the space in which one will be growing, the type of light being used for plants, and the availability of a freshwater source. And these are only a few! Let’s examine a few types of hydro growing systems and their most salient applications.

Deep Water Culture (DWC) – One of the most popular and impressive hydroponics systems is the deep water culture setup. DWC systems utilize a nutrient solution basin, usually a bucket or plastic tote, situated beneath the plants and acting as a source for water and nutrients. Plants are suspended from net pots located in the vessel’s lid and secured in a soilless medium such as Rockwool or expanded clay pebbles. The plant’s root system is allowed to dangle into the hydroponic nutrient solution. Air is pumped into the nutrient solution from an air pump connected to an air stone, providing aeration to the nutrient solution and the plant’s roots. Some variations include aeroponics, which incorporates misting emitters to keep roots wet, and aquaponics, which incorporates elements for raising aquatic animals along with the propagation of plants.

Ebb and Flow (Flood and Drain) – Ebb and flow systems operate by pumping water into a basin (often a hydroponics tray), which houses plants and then allowing the water to recede back into the reservoir. In other words, these are bottom-feed systems, filling the space around the plant’s container (and thus roots) with a nutrient solution that can be absorbed by the plant’s roots and the growing medium. Though quite productive, these systems require more space than a DWC setup, as there must be room for the hydro tray and the separate reservoir, making them less-than-ideal for small scale home growers.

Nutrient Film Technique (NFT) – The NFT technique is most often used in the production of hydroponically-grown crops such as lettuce or other leafy greens. Net pots hold plants and allow their roots to dangle into a large pipe that has been outfitted with holes to house the net pots. Nutrient solution is then pumped to one side of the pipe, which is banked to allow the solution to run out the other side. These setups work well for outdoor or greenhouse horticulturalists as they tend to be large and cumbersome.

There are many variations of each of these types of hydroponic systems. Some growers build recirculating deep water culture systems which allow for multiple buckets to be attached to the same reservoir, while others prefer to use a simple drip system and a soilless growing medium.

Picking the right hydroponic system is really a matter of your level of experience, your comfort level experimenting with new setups, and the amount of space with which you have to work. Of course, the type of system is only one factor in determining the quality and size of your harvests.

The Grow Environment

Possibly more significant than the type of system a grower chooses to implement is their ability to control the environment in which they are growing. While the system itself does a lot of the work of watering, it is entirely up to the grower to maintain proper conditions. No matter the size of the grow, there is no more critical factor to keeping your plants happy than proper control over the environment.

Air – Proper air circulation is crucial to hydroponic success and requires a few factors, namely a decent fresh air inlet and outlet, fans to move air within the grow room, and an exhaust fan to move old air out (usually through flexible ducting). Many growers attach their exhaust fan to an activated charcoal air filter to help reduce the smell. Often, growers employ various timers and controllers to ensure airflow is in sync with the grow room’s photoperiod, as well as moving air during the plant’s night cycle.

Humidity – While technically a consideration in the “air” category, humidity is so significant that it should be mentioned on its own. When dealing with indoor horticulture, the biggest concern is relative humidity (RH), or the amount of water vapour present in the air at a certain temperature versus the amount the air can hold at that temperature. The difference between these two figures is known as the vapour pressure deficit (VPD), a factor that can significantly impact plant health by controlling the stomatal opening and, thus, nutrient uptake. Growers often employ humidifiers and dehumidifiers to ensure consistent relative humidity and VPD, both of which directly affect a plant’s ability to grow.

Temperature – Maintaining a steady temperature in your grow room will play a critical factor in your success. Generally, cannabis grows best between 20-30℃ during the day period and 17-20℃ at night, so growers will often implement tools, such as temperature controllers, heaters, or air conditioners, to aid in maintaining these optimum levels and avoid fluctuations. At too high or too low of a temperature, plant growth can stunt, and plants become susceptible to pests and disease; moulds love low temperatures, for instance, while spider mites and powdery mildew thrive in hot grow rooms.

CO₂ – Carbon dioxide is to plants what oxygen is to people, meaning that they breathe it in and expel oxygen the same way we breathe oxygen and expel CO₂. Many choose to supplement their grow room with CO₂ by way of a tank with a regulator, though others opt to take alternative routes, such as hanging CO₂-generating mushroom bags around their grow room. Attaching a regulated tank to a controller, however, allows the grower to turn on their regulator and turn off their exhaust fan simultaneously, allowing supplemented CO₂ to buildup and ensuring it isn’t immediately sucked from the grow room.

Maintaining a proper grow room environment is perhaps even more important than a proper hydroponics setup itself. The impact of the environment on the health and well-being of your plants can never be underestimated.

Light

Light could fall under the larger umbrella category of environmental factors, but like humidity, its significance necessitates its own category. Light impacts your cannabis plants tremendously, so it’s important to consider a few key factors when deciding on your light source.

Spectrum – One primary consideration to make when picking a grow light is the spectrum of light that it produces. Many grow lights offer a limited spectrum, limiting the plant’s potential for photosynthesis. Metal halide (MH) lights, for instance, offer more blue light than red light, making them ideal for vegetative growth, while high-pressure sodium (HPS) bulbs offer more red light than blue, making them the better candidate for the flowering stage. Many LED lights offer a broader spectrum and promise to get you through a plant’s complete life cycle, though claims of true “full-spectrum” grow lights should be approached with scepticism.

Heat – Many grow lights produce a significant amount of heat, particularly high-intensity discharge (HID) lamps and those coupled with ballasts. The additional heat produced by grow lights can significantly impact grow room temperatures, necessitating further HVAC use and increasing costs.

Algae – Of particular import to hydroponic growers is the need to cover their nutrient reservoir and any places where light can reach the nutrient solution, such as tubing or level indicators. Water and nutrient solution exposed to light tends to develop algae and other pathogens, as well as being more susceptible to fluctuations in pH level, which will adversely impact the carefully curated microclimate.

Many factors can impact your success as a hydroponics grower, but dialling in a few key components can undoubtedly increase your odds. Above all, environmental control is critical, as the growing environment is every bit as significant as the system used, the genetics of the plants, or even how much time and dedication you offer your plants.