Cultivating Success: Understanding CO2 in Indoor Gardens

Maximising Growth with CO2 Enrichment

In the pursuit of optimal indoor cultivation, many growers are turning to the strategic use of carbon dioxide (CO2) to enhance plant growth. The benefits are indeed substantial, but it's crucial to tread carefully, as with great power comes great responsibility. In this blog, we'll explore the advantages of adding CO2 to your indoor garden and shed light on the potential dangers if not used judiciously.


Carbon Dioxide (CO2) is a vital component for robust plant development. Together with water and sunlight, CO2 facilitates photosynthesis, the process through which plants produce sugars and biochemical energy. This fundamental process is crucial for plant growth, as CO2 serves as a primary building block for plant tissue.


Enhancing the concentration of CO2 in the plants surrounding environment can significantly accelerate growth and improve yields. This is because photosynthesis is directly influenced by the availability of CO2. By elevating CO2 levels, growers can stimulate increased energy production in plants, resulting in larger and more plentiful flowers.


Ideally, plants thrive in an environment with approximately 1000 parts per million (ppm) of CO2, which surpasses the natural atmospheric concentration of around 400 ppm. To achieve this optimal level, some cultivators use CO2 supplementation techniques, such as introducing CO2 gas into their growing environment.


However, it is crucial to strike a balance, as excessive CO2 can pose risks to both humans and the environment, and its utilisation can incur significant costs and energy consumption. Growers must carefully weigh the benefits of CO2 supplementation against these potential drawbacks.


Moreover, maximising yield also involves optimising other environmental factors, such as light intensity and temperature. Under high-PPFD (Photosynthetic Photon Flux Density) lights, plants require CO2 levels ranging from 400 to 1400 ppm, depending on the growth stage, light intensity, and air temperature. Increasing light intensity promotes higher rates of photosynthesis, ideally complemented by elevated CO2 levels.


During the reproductive phase, temperatures up to 84°F (28.9°C) are recommended, with some growers even tolerating temperatures up to 90°F (32.2°C) to maximise growth potential.


In the realm of plant growth, the enzyme RuBisCO plays a crucial role in initiating the process of carbon fixation, which transforms CO2 and water into essential sugars during photosynthesis. However, this biochemical reaction is heavily influenced by temperature.


Under ideal conditions—ample sunlight, ambient CO2 levels around 300 ppm, and temperatures ranging from 5°C to 27°C—plants exhibit increased rates of CO2 absorption and sucrose conversion, leading to enhanced net photosynthesis.


Temperature regulation is equally vital, as higher temperatures facilitate enhanced gas exchange. During the reproductive phase, temperatures up to 84°F (28.9°C) are recommended, with some growers even tolerating temperatures up to 90°F (32.2°C) to maximize growth potential.


Yet, when leaf temperatures exceed 27°C, RuBisCO enzymes shift towards a reverse reaction, triggering photorespiration. As temperatures near 40°C, net photosynthesis turns negative, impeding growth as the plant consumes more carbon than it can use.


Fortunately, indoor growers have the advantage of manipulating their environment to create optimal conditions. Controlled environments enable precise regulation of temperature, CO2 levels, light exposure, and humidity, allowing growers to maximise growth potential, especially in warmer temperatures.


By understanding and adjusting these environmental factors, growers can harness the benefits of elevated temperatures to promote robust plant growth and yield.


 In short the benefits of CO2 Enrichment are:


  1. Accelerated Photosynthesis:

CO2 is a fundamental ingredient in the process of photosynthesis. By elevating CO2 levels in your indoor garden, you provide plants with more of this vital resource, leading to increased rates of photosynthesis. This, in turn, boosts plant growth, productivity, and overall yield.


  1. Enhanced Nutrient Efficiency:

Plants under elevated CO2 concentrations exhibit improved nutrient utilisation. This efficiency allows growers to optimise their nutrient regimens, leading to healthier plants with a reduced need for excessive fertilisation.


  1. Shortened Growth Cycles:

CO2 enrichment has been linked to shorter growth cycles. For growers, this translates to quicker turnover rates, allowing more cultivation cycles per year and ultimately maximising yield potential.


  1. Increased Tolerance to Stress:

Plants exposed to elevated CO2 levels often display greater resilience to environmental stressors, such as high temperatures or suboptimal light conditions. This adaptability is particularly advantageous in maintaining consistent crop quality.


The Balancing Act: Risks of Misusing CO2


  1. Asphyxiation Hazards:

While CO2 is essential for plant growth, excessive levels can pose risks to human health. Misuse of CO2 systems may lead to elevated concentrations in the air, resulting in potential asphyxiation hazards for humans and animals in the vicinity.


  1. Monitoring Challenges:

Proper CO2 management requires vigilant monitoring. Inaccurate readings or failure to maintain the desired levels can lead to unintended consequences, potentially causing harm to both plants and people.


  1. Fire Risks:

CO2 enrichment systems often involve the use of gas burners or generators. Improperly installed or maintained systems may pose fire risks, emphasising the importance of professional installation and regular system checks.


  1. Plant Stress at High Concentrations:

Paradoxically, extremely high levels of CO2 can lead to plant stress. This stress response, known as carbon dioxide toxicity, can manifest as leaf damage and impaired growth. Striking the right balance is crucial to avoid inadvertently harming your plants.


Striking the Right Balance: Best Practices for CO2 Enrichment


  1. Invest in Reliable Monitoring Systems:

 Install high-quality CO2 monitoring systems to ensure accurate readings and timely detection of any anomalies.


  1. Follow Recommended Guidelines:

Adhere to recommended CO2 concentration guidelines for both plant and human health. Typically, levels between 800-1200 parts per million (ppm) are suitable for most indoor gardens.


  1. Professional Installation and Maintenance:

Entrust the installation and maintenance of CO2 enrichment systems to professionals. Regular inspections and upkeep are essential for safety and optimal performance.


  1. Educate Yourself:

Before implementing CO2 enrichment, educate yourself on the specific requirements of your plants and the nuances of managing CO2 systems. Knowledge is your most powerful tool.


In conclusion, CO2 enrichment can be a game-changer for indoor cultivation, but it demands a nuanced approach. By understanding the benefits and potential risks associated with CO2, growers can harness its power responsibly, fostering a thriving indoor garden while prioritising safety and sustainability.


Products to use to achieve higher CO2 levels:


Slow release CO2:

Exhale & Exhale XL

Exhale CO2 Bag

Five Hole CO2

5 Hole CO2 Bag








Gemini CO2 bag

Gemini CO2 Bag



Fast release CO2:

CO2 Cannister - available instore only

Trolmaster CO2 Burner - available instore only

CO2 Gen bucket 5L & 10L- available instore only