Carbon Dioxide and Better Indoor Harvests

With carbon comprising as much as 40% of the plant material in harvest yields, CO₂ is a major plant nutrient that significantly drives plants’ growth rate, development, and ultimately, yield. Along with the light and water required for photosynthesis, carbon dioxide creates sugars that further drive growth and development.

As plants absorb carbon dioxide during the day, they release oxygen as a byproduct into the environment. (This process reverses at night, and plants “exhale” carbon dioxide just as animals and humans do, and absorb oxygen.)

Why it’s important to enrich your grow room with extra CO₂ during the day

• To prevent CO₂ depletion

Atmospheric carbon dioxide is about 300-360 parts per million (ppm), but indoor plants with fast growth and adequate light thrive on about 1200 ppm. Plants will use the naturally available CO₂ up very quickly, and if they’re not supplied with more, growth and development stops. Bringing the CO₂ level up to about 1200 ppm and then maintaining that during the day gives plants the energy they need to produce optimum yields.

• To boost growth

CO₂ enrichment during the day can boost plant growth and yields by 20 to 40%.

• To kill off pests

If your grow room is completely sealed, increasing CO₂ to 10,000 ppm for an hour can kill pests. (Caution: Growrooms must be *completely* sealed to prevent human CO₂ overexposure and potential health problems.)

Caveats

• Make sure all other elements are in balance

While most plants will thrive with CO₂ supplementation during the day, temperature, water and light must also be supplied at the proper levels for good results.

You can have too much carbon dioxide

Even though plants need CO₂, too much can be harmful. Plants that take in too much carbon dioxide can deteriorate when pushed to the limit during flowering cycles, and can produce fewer and smaller buds if this happens.

• DON’T supplement with CO₂ at night

At night, the photosynthesis process ceases and respiration begins. In respiration, plants exhale carbon dioxide and inhale oxygen. Supplementing with CO₂ is unnecessary and may actually stunt plant growth.