Since carbon dioxide (CO2) is essential in the process of photosynthesis, many cultivators assume that adding tons of CO2 is always a wise decision. While it's true that supplemental CO2 can increase plant yields, there's no guarantee this method will work. Extra CO2 only works in combination with other healthful growing habits. Anyone thinking about using CO2 for plant productivity needs to know how to add this compound to their space to achieve the best results.
How Does CO2 Help Plants Grow?
As mentioned above, CO2 is a necessary part of photosynthesis. Green plants like weeds need CO2, water, and light to create carbohydrates as “food” for growth. Without these three essential elements, plants wouldn't have the strength or energy to mature. Therefore, maintaining a steady stream of CO2 is essential for all plants.
While the atmospheric average of CO2 (i.e., 400 parts per million CO2) is enough for plants to grow, cultivators have noticed benefits from adding additional CO2 to their grow spaces. Increasing the available CO2 provides plants with extra nourishment, which often speeds up the growth process, improves healthy plant growth, and results in higher yields.
Some cultivators have observed that CO2 supplementation can boost the average growth speed of their weed plants by 20-100%, with total crop yields increasing by 20-30% compared to growing without added CO2.
When Should I Use CO2 In Grow Room
It’s best to start adding CO2 in grow tent or room when weed plants reach the mid-vegetative stage and continue through the first 2-5 weeks of flowering. For most photoperiod strains, the ideal time to begin CO2 supplementation is in the third week of vegetative growth, while for autoflowers, it's typically the second week.
While vegetative is the primary stage when plants are most responsive to CO2, it’s also beneficial to maintain CO2 levels during the flowering phase to promote faster growth, larger buds, and potentially higher yields.
What's The Ideal Amount Of CO2 For Plants?
The “ideal” amount of CO2 largely depends on a cultivator's space requirements, budget, and goals. While 1,500 ppm of CO2 can produce the maximum yield and the fastest growing time for most weed strains, the costs of extra equipment and energy may not merit these greater harvests.
Most cultivators agree that CO2 levels of 800 - 1,000 ppm are easy to achieve and manage while gaining the benefits from the increased carbon dioxide levels. However, we recommend prepared and professional growers raise the level to 1,500 ppm for the best balance of investment and outcome.
This is because most LED grow lights on the market are capable of high intensity of ~2,000 μmol/m²/s which is the matching light intensity for plants to handle 1,500 ppm of CO2. It is always our aim to leverage all available resources to increase returns.
Light Intensity
Even if you're adding 1,500 ppm of CO2 to your grow room, your plants can't absorb all of this CO2 if you don't have the proper light setting. You need to increase your light intensity for weed to use the supplemental CO2 in your grow tent.
When adding CO2 to your grow room, most cultivators recommend keeping your PPFD and CO2 ppm scores equal. For instance, if you're going to create an environment with 600 ppm CO2, make sure your grow light's PPFD is at least 600 μmol/m²/s. Similarly, if you want to max out your growth potential with 1,500 ppm of CO2, you need to grow lights that can achieve at least 1,500 μmol/m²/s.
As a rule of thumb, cultivators recommend setting your weed CO2 and PPFD levels as follows for the maximum benefits:
Seedling Phase: provide your plants with 200 - 300 μmol/m²/sPPFD, and simply with fresh air. The existing CO2 in the environment is enough and more will hurt the seedling's growth.
Vegetation Phase: strains will require 600 - 1,000 μmol/m²/s PPFDin this growth stage, and as you relatively increase the CO2 level to 600 - 1,000 ppm, the rate of photosynthesis will speed up amazingly. At this stage, the best-fixed CO2 level is 1,000 ppm, however, a more acceptable CO2 level is 800 ppm for most tent growers.
Flowering Phase: the ideal light intensity for flowering is 1,000 - 1,200 μmol/m²/s PPFDfor tent growers, so the relative CO2 level is 1,000 - 1,300 ppm.
Ultimate conditions: During the flowering stage, you can increase the light intensity to 1,500 - 2,000 μmol/m²/sand the CO2 level to 1,500 ppm. Growers who have reached this level have recorded a 100% increase in plant growth.
According to the above data, maintaining the CO2 level at 1,000 ppm throughout the growth stages is the most convenient and budget for home growers. For professional farmers, trying to achieve 1,000 ppm in the vegetation and handle the 1,500 ppm of CO2 in the flowering will gain the most.
Mars Hydro Providing Matching Grow Lighting
As long as you utilize supplemental CO2 in your cultivation, high-intensity LED grow lights are a must no matter what you are growing. For CO2 supplemental cultivation, Mars Hydro prepared three LED grow lights with qualified intensity to take full advantage of high levels of CO2 for perfect photosynthesis.
The FC8000 and FC-E8000 provide an average intensity of 1,400 μmol/m²/s, which is good if you plan to use 1000 ppm CO2 in your grow room.
The FC-E1000W provides the highest average intensity of 1800μmol/m²/s for farmers pursuing a 100% increase in photosynthesis rate and up to 30% increase in yield.
All 3 types of lights are dimmable, so they can easily match dynamic PPFD requirements throughout the plant growth cycle, whether they are used for vegetation or flowering. Check out Mars Hydro LED GROW LIGHTS COLLECTION for more plant lights to optimize your growing environment.
Temperature
When light intensity and CO2 concentration increase, the plant's tolerance to temperature increases correspondingly. On this premise, the plant needs higher temperatures as a driving force for perfect photosynthesis in this case.
Under typical conditions with a carbon dioxide concentration of about 400 ppm, the optimal growing temperature for weed is about 26-27°C (78-80°F). However, at CO2 concentrations above 1,000 ppm, plants can grow as high as 96°F (36°C), where photosynthesis peaks. In summary, most indoor growers agree that a temperature of 30°C (86°F) is ideal for both growth rate and ease of management.
However, remember that precious terpenes will start evaporating at 26 °C (78 °F), so it's not always good to keep temperatures beyond that level. Keeping your grow room cool is more beneficial when entering the 2nd half of the flowering season. Of course, the temperature control depends on your needs.
How To Calculate The CO2 You Need For Your Space
In addition to calculating your light intensity levels, cultivators need to take some time to figure out how much CO2 they can add to their space. This will help you make the best use of your grow area and figure out the average cost of CO2 per cubic foot.
The simplest way to gauge how much CO2 you can fit in your space is to use the following formula:
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Your grow space's width(ft) x length (ft) x height (ft) x ideal CO2 levels in parts per million (ppm) = CO2 in cubic feet
To make this equation clearer, let's run through an example. Suppose your grow room measures 8 x 8 x 7 ft, and you want to put 1,000 ppm of CO2 in your space. In this case, you would need to multiply 8 x 8 x 7 x 0.001 to get a figure of 0.448. In this example, you'll need 0.448 cubic feet of CO2 to achieve your 1,000 ppm CO2 level.
The Best Ways To Apply CO2
There are a few ways to add CO2 to your grow space, each of which is suitable for different areas and budgets.
Portable “CO2 bags” are only good in small grow environments. These inexpensive products typically contain substances like mycelium that naturally release CO2 once you open the bag. While these items are relatively cheap and easy to use, they won't give off enough CO2 for a larger grow area.
CO2 tanks are the most versatile method for growing tents and small grow rooms. Similar to grow bags, CO2 tanks release CO2 into the atmosphere once you open them. However, the CO2 tends to spread further and penetrate deeper than a small CO2 bag. Due to their ease of use and high efficiency, CO2 tanks tend to be the most commonly used CO2 delivery method in cultivation circles.
CO2 generators are involved in large-scale commercial planting. The main benefit of generators is that they will supply the highest quantity of CO2. However, since these generators use a flame to produce CO2, they require extra maintenance and energy costs. Also, you have to factor in the extra heat CO2 generators give off into your grow space.
Conclusion
As a final piece of advice, please remember that CO2 won't “magically” make your weed grow faster and bigger. Like any good supplement, CO2 only works well when all other factors are accordingly optimized. While adding CO2 has its benefits, cultivators should always focus on general gardening skills over monitoring CO2 levels.
FAQ about Using CO2 for Plants' Productivity
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Do Plants Take In CO2 At Night?
Without light, CO2 cannot be absorbed by plants. At night, plants switch from photosynthesis to respiration, taking in oxygen and releasing carbon dioxide. Therefore, adding extra CO2 to your grow space at night is not beneficial.
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How to homemade CO2 for plants?
You can create homemade CO2 for plants by fermenting a mixture of sugar, yeast, and water, or by combining baking soda and vinegar, both of which release carbon dioxide that can benefit plant growth.
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How to increase CO2 in greenhouse?
To increase CO2 levels in a greenhouse, use compressed CO2 tanks for precise control or create CO2 through fermentation with sugar and yeast. Propane or natural gas heaters also release CO2 during combustion, while composting systems can generate CO2 from organic matter.
