Even though CO2 levels in the air are much lower today at around 400 PPM, plants are still able to use CO2 levels at the higher concentrations, allowing them to produce more energy from the same amount of light. Growers can take advantage of this increased growth by providing extra CO2. That means in order for CO2 enrichment to be the most effective, you want to maintain levels up to 1500 PPM of CO2 in your grow space with very bright light.
CO2 supplementation works best when everything else in the grow space has already been optimized, and for most growers, a little optimization may result in even bigger returns on yields than adding CO2! If you're using smaller grow lights with lower light levels, you will need less CO2! Plants should have fast & healthy growth – No nutrient problems and no pest problems if possible. It will also maximize your yields by using plant training. Healthy and vibrant plants respond really well to extra CO2! Now let's learn how to use CO2 enrichment right because I've seen a lot of misinformation out there, causing many cannabis growers to waste a lot of money on ineffective CO2 methods. I want to help you set it up the right way and enjoy the benefits!
After years of research and study by commercial greenhouse growers, we've learned exactly what's needed to get the benefits of extra CO2. Today I will share everything I wish I’d known about CO2 when I started growing, so you'll know exactly how you can use CO2 for faster growth and increased marijuana yields. Some people (especially companies selling poor CO2 products) will try to trick you into thinking that CO2 is some magical supplement you add to your grow room to make plants grow better. There are good ways to add CO2… and there are ineffective ways. The two most effective CO2 enrichment methods are using a CO2 generator or buying tanked or bottled CO2, combining your enrichment method with a CO2 regulator or timer. Don't worry, we're going to walk you through the whole thing. A good rule of thumb is you should have 7,500-10,000 lumens per sq foot in your grow area to get the full benefits of enriching with CO2 when supplementing with 1200-1500 PPM. You need high-powered grow lights like HPS bulbs or bigger LEDs for this rule to hold true. If you're using less light, you'll need less CO2 to be effective, though you won't be getting as much an increase in growth compared to if you were using stronger lights. To figure out if you have enough light to supplement up to 1200-1500 PPM of CO2, determine out how many lumens your bulbs gives off. Then find the square footage of your space (length x width). Examples of Setups with Enough Light for CO2 Injection up to 1500 PPM. If you're using smaller lights with lower light levels, you will need less CO2! Learn more about HPS grow lights and LED grow lights. 2.) Seal Your Grow Space (optional) Regular air only has about 400 PPM of CO2 so if you don't seal your grow area, any CO2 you add will slowly leak out. While this isn't important if you only plan on adding relatively small amounts of CO2, if you want to maintain high levels of CO2 up to 1200-1500 PPM of CO2 in the air, you should seal your grow space in order to prevent yourself from wasting lots of CO2. You should seal your grow room to keep all the extra CO2 inside if you're adding a lot of CO2. Some things to keep in mind when sealing your grow space: Temperature – If you're supplementing at the highest levels, many growers recommend maintaining temperatures between 85°F (30°C) and 95°F (35°C) in your grow space for extra CO2 to be most effective, though it's important to watch plants closely for signs of heat stress as some plants can handle heat better than others. Humidity – You should keep humidity below 60-70% to prevent mold and other problems. Although most grow rooms don't have humidity this high, I mention this because keeping humidity low can be difficult if end up creating a sealed room. So for bigger operations some growers may need to use a dehumidifier. This means that you need to get rid of any possible air leaks when the grow space is closed. If You Do Want to Seal Your Room, Get the Right Hood/Reflector!
Most growers need to cool their lights to keep temperatures in the right range. When chosing a reflector for your grow light, it's important to get one that is able to be cooled via ducting, without letting any of that air get inside the grow room and bring down your CO2 levels. Winged Reflectors ("Bat Wings") If all the air in your grow space is being re-circulated constantly, the CO2 levels start to drop as your plants use it up in the photosynthesis process. In this case you may want to supplment CO2 in an open room. Bat wing reflectors are a common choice, and they'll let you keep several grow lights in an open room that's being supplemented with CO2. A winged hood is basically just a reflector with a socket for your bulb and a plug to connect to your ballast. They are the simplest type of "hood" for HID grow lights and also tend to be the least expensive. However, wings aren't good for controling heat because they do not contain the heat from the bulb (like the next options you'll see listed here) and they also have no built-in cooling features. With a winged reflector, the heat from the bulbs will basically be radiating downward from the bulbs onto your plants with nothing in between to shield your plants from the heat. One cool thing about batwings is that since they do not have glass between the bulb and the plants, they can deliver up to 10,000 lumens or more than the same bulb in an enclosed hood because the light doesn't have to pass through the glass before it reaches your plants.
But since they're hard to cool you may have to keep them further away from your plants, which diminishes that benefit. When it comes to your grow lights, a "Cool Tube" style hood is an effective reflector when a bigger hood reflector won't work, but you need to keep the air cooling the grow lights separate from the air in the grow room.