How Much CO2 Should I Add to My Cannabis Grow?

How Much CO2 Should I Add to My Cannabis Grow?

Image 47

Optimal CO2 Enrichment for Cannabis Cultivation: Boosting Your Grow with the Right Levels​

Growing cannabis has transformed from an underground hobby to a professional industry. With this evolution, techniques have been refined, and one fundamental aspect is the addition of carbon dioxide (CO2) to cannabis grow environments. Now, to every grower’s question: "How much CO2 should I add to my cannabis grow?" let’s delve into the details that will elevate your grow to its fullest potential.

Understanding the Importance of CO2 for Cannabis Growth​

CO2 is crucial for the process of photosynthesis, whereby plants convert light, water, and CO2 into glucose for growth. Cannabis, like other plants, thrives on the right balance of these elements. Without adequate CO2, even the most powerful lights and nutrient-rich water will fall short in fostering optimal growth.

The Ideal CO2 Levels for Cannabis Cultivation​

The ambient level of CO2 in the atmosphere is about 400 parts per million (ppm). Cannabis plants can, however, utilize much more. The sweet spot for CO2 concentration in a grow room is typically between 1,200 to 1,500 ppm. Research suggests that levels above this can supercharge photosynthesis, leading to faster growth rates and potentially higher yields.

Calculating the Right Amount of CO2​

Calculating the CO2 requirements involves considering the size of your grow room and the type of CO2 system in use. Here’s a basic formula:

CO2 needed (in cubic feet) = Grow room volume (in cubic feet) × (Desired CO2 level in ppm - Ambient CO2 level in ppm)

For example, if your grow room is 1,000 cubic feet and you want to raise the CO2 level to 1,300 ppm from an ambient level of 400 ppm:

CO2 needed = 1,000 × (1,300 - 400) = 900,000 cubic feet of CO2

You would then divide this number by the concentration level of your CO2 source to determine the actual flow rate per minute.

Methods of Adding CO2​

There are various methods for introducing CO2 into a grow room:

CO2 Generators: These burn fossil fuels to produce CO2. They are effective but also produce heat, which may affect the grow room temperature.

Compressed CO2 Tanks: These are a common choice for smaller operations. They are easy to install and control but require regular refilling.

CO2 Bags: These bags contain a substrate that produces CO2 as it decomposes. While low maintenance, they may not be adequate for larger setups or achieving higher ppm levels.

DIY Methods: Fermentation or vinegar and baking soda reactions can produce CO2 but are unpredictable and often not viable for consistent supply.

Controlling CO2 Levels​

To maintain the optimal levels, CO2 is often added in conjunction with an automated system that measures the concentration and administers the gas accordingly.

Monitors and Controllers: Devices can track CO2 levels and regulate the release from generators or tanks as needed.

Timers: Synchronized with light cycles, CO2 is often added during the daylight period when plants photosynthesize.

Safety Considerations​

When dealing with added CO2, safety is paramount. Levels of 1,500 ppm are safe for plants but can be harmful to humans with prolonged exposure. Adequate ventilation, along with CO2 monitors that are designed to turn off the system if levels get too high, ensure both plant and human welfare.

Understanding the Cost-Benefit Ratio​

CO2 enrichment can lead to more significant returns, but it’s also an added expense. It’s important to weigh the initial setup costs, ongoing expenses, and potential gains in yield when deciding whether to implement CO2 supplementation.

The Role of Ventilation​

Even with an excellent CO2 setup, if your grow room lacks proper ventilation, plant health can suffer. Fresh air exchanges are vital to remove excess humidity and to supply fresh CO2, particularly in setups without added CO2 systems.

Timing CO2 Supplementation for Maximum Impact​

Introducing CO2 during the vegetative stage can accelerate growth, but it’s during the flowering phase that CO2 can truly boost yield. This is when cannabis plants are most photosynthetically active. Combined with optimal lighting and nutrition, a CO2-enriched environment can make all the difference.

Environmental and Strain Considerations​

Not all strains respond equally to CO2 enrichment. Some may not exhibit improved yields at all, so it’s crucial to know your strain. Additionally, CO2 supplementation is best used in controlled environments—outdoor grows don’t offer the sealed space necessary for concentration management.


In summary, enriching your cannabis grow with CO2 can lead to improved growth rates and yields. By maintaining CO2 levels between 1,200 to 1,500 ppm during the light cycle and ensuring adequate ventilation, your plants will have what they need for superior photosynthesis. Always consider the cost, safety, and potential benefits for your specific grow operation and strain. Remember that while CO2 can be the catalyst for an abundant harvest, it’s the synergy of all growth factors that leads to success.

Whether you are a hobbyist or a commercial grower, understanding and utilizing CO2 enrichment can give you an edge in cultivating cannabis. Approach this enhancement methodically and safely, and you may find that the addition of CO2 is the breath of life that takes your grow to new heights.
  • Like
Reactions: drewski85
First release
Last update
4.00 star(s) 1 ratings

More resources from logic

Top Bottom