What Is Hydroponic Agriculture?

Hydroponic farming is an advanced type of soilless agriculture that lets crops grow in water, rather than soil. In this technique, plant roots are submerged in water that contains all the of the nutrients they need.

Growers around the world grow vegetables, herbs, leafy greens, and even cannabis, in hydroponic greenhouses, indoor grow rooms, and vertical farms. It’s also touted as an efficient method of urban agriculture, along with aeroponics.

There are several types of hydroponic systems. The most common of which are nutrient film technique (NFT), deep water culture (DWC) and ebb & flow, also referred to as flood and drain.

Why Is Hydroponic Climate Control More Challenging?

Growing hydroponically has numerous advantages. It helps optimize growth, leading to larger yields and higher quality, reduces land use, and drastically saves on water.

However, water provides much less of a buffer than soil. It’s more sensitive to changes in the environment, such as temperature. So, the roots are left more exposed, and the plants are more sensitive.

Any change in the environment will have a quicker impact when it comes to hydroponic systems. For example, if temperatures suddenly drop, it will affect the plants much quicker in a hydroponic setup, than in a traditional soil-based setup.

Overall, hydroponic gardens require a lot of control. So, the need for climate control systems is greater than that of traditional greenhouse growing.

Hydroponic Climate Control Parameters

Controlling the growing environment and creating the optimal climate isn’t unique to hydroponic setups. However, hydroponic grow rooms and greenhouses are more sensitive, so setting up the right environmental controllers is critical.

Creating Ideal Temperatures

Temperature is one of the most basic climate parameters. Most greenhouses and indoor grow rooms use temperature controllers in one form or another to heat or cool the space.

Every plant has its ideal temperature range. So most growers use heating or cooling systems, such as HVAC, heat pumps, wet pads, or air conditioning.

The most critical difference between traditional and hydroponic temperature control, is the need for consistency and reliability. Water is much more easily impacted by temperature than soil. So, any change to the climate will have a quicker effect on the plants.

For example, a sudden 30-minute power shortage may not affect soil temperatures enough to harm the plants. However, as water is more sensitive to the environment, its temperature might change quickly, impacting the roots and stressing the plant.

On a larger scale, this may cause large amounts of plants to die, leading to massive yield loss. So having reliable temperature controllers and minimizing temperature fluctuations is crucial to maintain successful hydroponic grows.

Providing and Balancing Lighting and Radiation

Light is at the heart of horticulture. It’s the key to photosynthesis, and therefore plant life. But it also has major impacts on other growing conditions, such as temperature and humidity.

Greenhouse and grow room climate control systems are often based around lighting. Of course, hydroponic greenhouses can utilize the sun during the day, while indoor facilities rely solely on grow lights. Cheap and efficient lighting has become much more common in recent years, with LED lights replacing the older HPS technology.

One important thing to consider when lighting a hydroponic farm, is that lights, even efficient ones, emit heat and radiation. Besides raising temperatures, they also cause plants to transpire a lot more water. So it’s important to compensate by adjusting the water supply.

Controlling Humidity

Humidity is one of the most important climate factors for plant development. Growers often measure and monitor it in relative humidity (RH) or vapor pressure deficit (VPD).

As plants are always transpiring, even in hydroponic settings, humidity is constantly on the rise. When uncontrolled, humidity will inevitably reach 100%, leading to disease and mold outbreaks, like powdery mildew or botrytis (gray mold).

Using humidity controllers, such as dehumidifiers, is the only sure-fire method to control humidity.

Some greenhouse operators use ventilation in combination with heating to combat humidity. But this method is much less efficient in terms of energy, driving heating costs up. Additionally, it can’t ensure successful results 100% of the time, so disease may still break out.

Using dehumidification systems to reduce humidity has numerous benefits. Maintaining ideal humidity levels stimulates plant growth, leading to higher quality produce and larger yields. It also helps reduce pesticide and fungicide use, making it the ultimate choice for organic crops.

When it comes to hydroponic humidity control, dehumidifiers provide the consistency and reliability necessary to ensure total climate control.

Maintaining CO₂ Levels

Another climate parameter that growers should consider in any form of controlled environment agriculture is CO₂ concentrations.

Carbon dioxide is a critical part of photosynthesis. It’s the raw material necessary for the plant to produce the glucose it needs in order to develop. So to optimize cultivation and grow large, healthy and high-quality plants, CO₂ levels should be just right.

Indoor and greenhouse growers often supplement their facilities with CO₂ injections. However, it quickly escapes when opening the greenhouse or ventilating. So, one of the best ways to control CO₂ is by keeping the space closed. This ties in well with hydroponics and other advanced cultivation methods, such as aquaponics or aeroponics, as there’s already a need for tight control.

In most closed or semi-closed environments, the biggest problem with retaining CO₂ is humidity. As humidity rises, growers release it through ventilation, releasing the carbon dioxide along with it. So, although the two may not seem directly connected, controlling humidity is actually one of the best ways to retain CO₂.

Hydroponic Climate Control Requires Total Control

Hydroponic cultivation is without a doubt a highly efficient way to grow. It lets growers maximize their space and grow large amounts of produce in a short period. It’s also considered part of the next generation of horticulture, and urban agriculture specifically, along with vertical farming.

When it comes to climate control, hydroponic farms generally require the same grow room climate control systems used in other controlled horticulture environments. However, the most important difference is the necessary level of control.

Traditional, soil-based greenhouses and grow rooms may be able to deal with minor challenges and climate fluctuations. But hydroponic growers can’t allow themselves as much of a margin for error, requiring more comprehensive and reliable control.

For more information on hydroponic climate control and dehumidification, please feel free to contact us!