CO₂ in cannabis cultivation – increasing efficiency and optimal use

Carbon dioxide (CO₂) plays a crucial role in plant growth, including cannabis. By enriching CO₂ levels, photosynthesis can be optimized, leading to higher yields and faster growth cycles. However, using CO₂ effectively requires a thorough understanding of optimal conditions to maximize its benefits and avoid unwanted side effects.

Why is CO₂ Important for Cannabis Cultivation?

Plants need CO₂ for photosynthesis, the process by which light energy is converted into chemical energy. Increasing CO₂ concentrations allows plants to grow more efficiently, especially in high-light environments.

Benefits of Additional CO₂ in Cultivation

• Faster Plant Growth: Increased CO₂ concentration accelerates photosynthesis, leading to faster plant development.
• Higher Yields: Plants can build more biomass, which is particularly beneficial for commercial growers.
• Better Tolerance to High Temperatures: Higher CO₂ levels allow plants to grow efficiently even at elevated temperatures.
• Efficient Light Utilization: Especially in LED-based growing systems, CO₂ can maximize the energy output of lighting.

Optimal CO₂ Concentration for Cannabis Cultivation

The natural CO₂ content in ambient air is around 400 ppm (parts per million). However, plants can utilize higher concentrations of up to 1500 ppm to accelerate their growth.

Temperature and Humidity Adjustment

When supplementing with CO₂, the environmental temperature should be slightly increased to optimize absorption:

• Recommended temperature with CO₂ enrichment: 26–30°C
• Relative humidity: 50–70% to optimize transpiration and CO₂ uptake

Methods for CO₂ Enrichment

There are various ways to introduce CO₂ into the grow space. The choice depends on the grow area size, budget, and desired control over CO₂ concentration.

1. CO₂ Bottles and Regulators

One of the most precise methods is using CO₂ bottles with a pressure reducer and a regulator to control CO₂ release.

• Advantages: Precise control, immediate effect
• Disadvantages: Higher initial cost, requires regular refilling

2. CO₂ Generators

CO₂ generators burn propane or natural gas to produce CO₂.

• Advantages: Cost-effective for larger grow rooms
• Disadvantages: Produces heat, increases room temperature

3. CO₂ Pads and Bags

For smaller grow spaces or grow tents, CO₂ pads or bags containing mycorrhizal bacteria offer a simple solution.

• Advantages: Affordable, no technical expertise required
• Disadvantages: No precise control over CO₂ levels

4. Dry Ice

CO₂ can be released by evaporating dry ice.

• Advantages: Easy application, no permanent installation needed
• Disadvantages: Limited duration, not suitable for long-term growing

How to Use CO₂ Correctly?

1. Add CO₂ Only When Lights Are On

CO₂ should only be added during the light phase, as plants can only utilize it for photosynthesis in the presence of light.

2. Ensure Effective Distribution

CO₂ is heavier than air and accumulates at the bottom. Therefore, fans should distribute the gas evenly throughout the room.

3. Monitor CO₂ Concentration

A CO₂ meter is essential to ensure that levels are neither too high nor too low.

4. Avoid Overdosing

Too much CO₂ can be ineffective and will not promote growth beyond a certain point. Above 2000 ppm, CO₂ can even be toxic to humans.

Common Mistakes When Using CO₂

1. Using CO₂ Without Sufficient Light

If plants do not receive enough light, the additional CO₂ supply cannot be efficiently utilized.

2. Incorrect Placement of the CO₂ Source

Since CO₂ is heavier than air, it should be released above the plants and distributed using fans.

3. Incorrect Temperature Levels

If temperatures are too high or too low, plants cannot optimally absorb CO₂.

4. Inadequate Air Circulation

Without fans, CO₂ may distribute unevenly, benefiting some plants while others receive none.

CO₂ in Combination with Other Growth Factors

CO₂ alone does not automatically lead to better yields. To achieve the best results, other growth factors must also be optimized:

Is CO₂ Worth It for Home Growers?

For home growers, CO₂ enrichment is only beneficial if all other factors are already optimized. In small grow tents with limited light and without high-performance lighting, CO₂ often provides little benefit. However, for larger setups with high-intensity LED or HID lamps, it can significantly increase yields.

Conclusion: Using CO₂ Efficiently for Maximum Yield

CO₂ can be a powerful tool to boost cannabis growth and yields. However, those who choose to enrich CO₂ must consider optimal conditions such as light, temperature, and air circulation. Proper application leads to healthier plants and more efficient resource utilization while avoiding mistakes such as overdosing or incorrect placement.

Products for CO₂ Supply at Cannadusa

MotherNature CO2 Bucket 5L incl. Pump - €75.90

MotherNature CO2 Generator Refill Bag - €64.90

Caluma CO₂ Tablet - €16.99