Ambient CO2 concentration is 300-400 parts per million (ppm), but be aware that many cities such as Phoenix, Los Angeles, and Denver often have intermittent “CO2 domes” floating on top of them that add CO2 and other air pollutants to your urban air. Check with your local air quality agencies about that. Urban air pollution is a killer.
Inside your marijuana grow room you can add CO2 to increase concentrations to 1000-1500 ppm so your plants grow about 25% faster in grow phase and produce 10-35% more harvest weight.
It is a matter of opinion, but many believe that added CO2 also helps your marijuana plants produce more THC.
Extra CO2 in your hydroponics room enables your plants to handle more heat. With ambient levels of CO2 in the regular range, you keep your hydroponics room temperature at 70-74F. But when you’ve added CO2 to create 1000-1500 ppm , your cannabis plants tolerate temperatures as high as 85F.
When you increase CO2 concentrations in your grow room air, you also have to feed your marijuana plants more hydroponics nutrients, more light, and more water. If you don’t give them more food, water and light, the extra CO2 may hurt your plants instead of help them.
You can use dry ice, fermentation, and a variety of contraptions to add CO2. Dry ice and fermentation are cheap and simple, but you can’t precisely control how much CO2 they produce.
Serious marijuana growers use hydroponics devices that distribute CO2 from tanks or produce CO2 by burning propane or natural gas. Distributing from tanks requires using the proper regulator to control output, but even then you may have a hard time getting precise levels. It’s important to have precision control over CO2 levels because too much CO2 (above 1500 ppm) can damage your plants.
Tank CO2 costs a lot and the tanks weigh quite a bit. You create security risks just to procure and get refills of CO2 tanks. That’s why most marijuana growers choose CO2 generators that burn propane or natural gas. If your grow site is already connected to municipal natural gas, you may be able to adapt your device to feed off the municipal supply. Or you may have to buy tanks of propane or natural gas. Consider the security and logistics of how you will source propane or natural gas before you invest in a CO2 generator.
When you add CO2, you have to change some of your hydroponics grow room set-up to accommdate the addition. People growing in vented hydroponics rooms must carefully time venting so it doesn’t just remove added CO2 from the grow room.
This is tricky because CO2 generators add humidity and heat to your hydroponics room. You use more electricity to dispose of the extra heat and humidity, and you have to figure out how to remove heat without removing the CO2 you just added. And remember, you only add CO2 during the lights-on cycle.
Combine the heat from your lights with the heat from a CO2 burner, and you may need an air conditioner if you don’t already have one. You may also need a chiller to keep your hydroponics nutrients water around 68F. This helps your hydroponics plants handle higher air temperatures.
CO2 generators burning natural gas or propane have a flame, and where flame and fuel are, fire risk is ever-present. Problem is, most hydroponics CO2 generators don’t have enough safety features to eliminate fire risk.
I use a special, new kind of CO2 generator that’s water-cooled and has more safety features than any other generator, including automatic shut-off, no pilot light, a valve that can handle pressurized municipal gas, an overheating sensor and a tipping sensor. This kind of built-in security and reliability give your CO2 project a solid foundation.
Look into CO2 controllers that can integrated with hydroponics climate controllers that monitor and run aeration, fans, CO2 and other factors to ensure optimum temperature, air movement, humidity and CO2. You really need to be able to precisely monitor CO2 ppm, and monitors are one of the few ways to do it.
One last piece of advice: CO2 is bad for you. Avoid going in your room when you have your CO2 boosted above 370 ppm.
The bottom line is that adding CO2 to your hydroponics marijuana grow room will pay for itself and add value to your grow room, even with the costs associated with a CO2 generator, extra light, water and nutrients, and mitigating extra heat. The payoff is more crop cycles per year and heavier yields. It’s a fact that adding CO2 gives you more and better marijuana at a good cost to benefit ratio.
I suggest you go to your hydroponics store today and look at their CO2 generators and CO2 monitoring gear as you realize that adding CO2 is a gold mine for hydroponics marijuana growers.