How to use CO2 for Optimal Cannabis Cultivation

The Role of CO₂ in Cannabis Growth

Carbon Dioxide (CO₂) is a chemical compound that fills the atmosphere in a gas state and is essential for healthy plant growth. Together with water and sunlight, carbon dioxide plays an important role for crops to create sugars.

Cannabis plants, like all plants, use carbon dioxide during photosynthesis to produce biochemical energy. In fact, carbon dioxide is one of the primary building blocks of plant tissue.

Benefits of CO₂ for Cannabis Cultivation

Increasing the concentration of CO₂ in the air around cannabis plants can help promote faster growth and higher yields. This is because photosynthesis is directly linked to the amount of CO₂ available to the plant. By increasing the concentration of CO₂ in the air, growers can help cannabis plants produce more energy, which can lead to larger and more abundant flowers.

Typically, cannabis plants thrive in an environment with a CO₂ concentration of around 1000 parts per million (ppm), which is higher than the natural concentration in the atmosphere (around 400 ppm). Some growers use CO₂ supplementation techniques, such as introducing CO₂ gas into their growing environment, to raise the concentration of CO₂ and boost plant growth.

However, it’s important to note that while CO₂ can be beneficial for cannabis growth, excessive amounts of CO₂ can be harmful to humans and the environment. Additionally, the use of high levels of CO₂ in the cultivation of cannabis plants can be costly and energy-intensive. It is important for growers to balance the benefits of CO₂ supplementation with the potential risks and costs.

How to Enrich Your CO₂ using LED Lights

Typical CO₂ levels for growing cannabis under high-PPFD (Photosynthetic Photon Flux Density) lights range from 400-1400 ppm and depend on the plant’s growth stage, as well as the light intensity and air temperature. As plants grow throughout the production cycle, increasing light intensity will promote higher rates of photosynthesis, which is ideally supplemented by increasing CO₂ levels to enhance photosynthesis. At PPFD of ≥ 500 umol/m²/s, the recommended CO₂ levels should be ≥ 800 ppm (Figure 1).

Temperature also plays an important role in accelerated gas exchange. High-PPFD light and high CO₂ concentrations must pair with higher temperatures to induce sufficient transpiration. For instance, some cultivators may run 1,400 ppm/1,000 umol⋅m^-2⋅s^-1 while keeping their room temperature at 75° F (23.9 C), which limits the benefits of CO₂ enrichment and supplemented photons. In the reproductive phase of growth, temperatures as high as 84° F (28.9° C) are recommended and some growers may even find 90° F (32.2° C) acceptable.

In conclusion, while CO₂ plays an essential role in cannabis cultivation, it is important to understand the balance of benefits and potential risks of too much CO₂. The use of high-PPFD lights can also help to increase rates of photosynthesis which can lead to maximize growth. Contact a Fluence Expert today to learn how our LED lighting systems can help increase gains in your greenhouse facility.