CO2 Enrichment: Boost Growth and Beat Heat Stress

How CO₂ Enrichment Supercharges Hydroponic Growth

In this blog, we’re exploring CO₂ enrichment—a powerful yet often overlooked technique to maximize yield and help your plants tolerate heat stress in hydroponic grow rooms or greenhouses.

If you’re a more advanced grower looking to squeeze every ounce of performance from your crops, this one’s for you.

What Is CO2 Enrichment?

CO₂ enrichment involves increasing the carbon dioxide concentration in your grow space beyond normal atmospheric levels. Currently, ambient CO₂ levels are around 426 parts per million (ppm)—a figure that’s risen due to human activity but still far below what plants optimally require for growth.

Most experienced growers aim to raise this to around 1,000 ppm, which can significantly boost photosynthesis and growth when other conditions like lighting, temperature, and nutrients are already optimized.

Key Benefits of CO2 Enrichment

🌱 1. Accelerated Growth

When CO₂ levels rise, photosynthesis speeds up—meaning your plants grow faster and stronger.

☀️ 2. Increased Heat Tolerance

CO₂ helps plants better withstand heat stress, especially valuable during summer heat waves or in high-light environments.

💸 3. Better ROI (When Done Right)

Used correctly, CO2 enrichment delivers better yields and higher quality produce, making it a profitable upgrade for commercial and serious hobbyist growers.

When Should You Use CO₂ Enrichment?

🚫 Not for beginners.
If your grow room isn’t dialed in—with stable lighting, temperatures, airflow, and nutrient delivery—CO₂ won’t help much. Plants can only utilize higher CO₂ when other growth-limiting factors are removed.

Common Methods of CO₂ Delivery

Let’s break down the most popular options:

🔥 1. Burners

• How it works: Combust fossil fuels to release CO₂.
• Best for: Large-scale greenhouses.
• Pros: Effective and cost-efficient for volume.
• Cons: Fire risk, increased humidity and temperature, and possible nitrogen oxide toxicity over 1,000 ppm.

🧯 2. Canisters

• How it works: Release pure compressed CO₂ using a regulator.
• Best for: Controlled indoor environments.
• Pros: Clean and precise.
• Cons: Expensive, heavy, and regulators may freeze with high output.

🧪 3. Fermenters

• How it works: Yeast or fungi consume sugars to release CO₂.
• Pros: DIY and affordable options exist.
• Cons: Can be smelly, slow, and inconsistent unless pumped and monitored.

⚗️ 4. Bicarbonate + Citric Acid

• How it works: React sodium (or potassium) bicarbonate with citric acid to release CO₂.
• Best for: Small-scale, hands-on growers.
• Pros: Affordable, controllable, and can yield usable potassium citrate fertilizer as a byproduct.
• Cons: Manual, needs CO₂ monitoring for precision. Expensive when cost per kg of CO₂ is taken into account.

Bonus Methods (Yes, Really!)

• You, the grower. Spending time in your grow room means you’re exhaling CO₂!
• Pets. Cats or guinea pigs chilling in your space can also contribute.
• Just like King Charles talks to his plants—you can too! You’re giving them carbon dioxide in the process. 😉

Tools to Help

To make CO₂ enrichment effective, invest in a CO₂ meter or monitor. These are now relatively inexpensive and available at most grow shops or online. They’ll help you keep CO₂ levels safe and effective—ideally around 1,000 ppm.

Final Thoughts

CO₂ enrichment can be a game-changing technique for hydroponic growers—but only when implemented in a well-optimized grow environment. Done right, it enhances growth, yield, and plant resilience.

If you’re ready to level up your grow room, start exploring the right CO₂ method for your setup. Have experience with CO₂ enrichment or a favourite method? Drop a comment—we’d love to hear what works for you!

Any if you are looking for an excellent fertilizer to help out with growing from seed to harvest, check out Liquid Gold

Article by Dr Russell Sharp

If you would like to keep up to date with subjects just like this, you can listen to both our podcasts! Links can be found bellow:

Hydroponics Daily Podcast: https://open.spotify.com/show/207T7p7fw9sPjINfSjVXW2

Cereal Killers Podcast: https://t.co/eSEbBkTVHl