A cannabis grow requires a stable supply of fresh air to replenish carbon dioxide and keep humidity, temperature, and photosynthesis at a constant level. Indoor growers can easily meet this need with a few simple measures.
Keeping air moving in and out of your grow room reduces the presence of fungus, mold, and mildew. It also helps fight against common pests like fungus gnats and spider mites, which thrive in stagnant air.
Temperature
Air circulation is one of the most important aspects of a good cannabis grow. Whether it’s a simple oscillating fan in your grow room or a large industrial-sized exhaust system, the right ventilation is crucial to healthy growth and optimal yield.
When growing indoors, you’re always trying to duplicate the conditions that cannabis thrives under outdoors. This means creating the perfect temperature, humidity, oxygen and carbon dioxide levels for your plant.
The ideal temperatures for cannabis are between 68 degrees and 77 degrees Fahrenheit during the day and 62 degrees to 72 degrees F at night. Keeping the temperature steady throughout the growing process is important, as too much fluctuation can cause stress and even kill your crop.
While many indoor growers focus on the lighting schedule and nutrient management, air flow is just as crucial for optimal production. Proper airflow not only keeps the temperature steady, but it also helps keep your grow space ventilated and free of pests.
As plants mature, they need more and more air to breathe in order to grow properly. Stagnant air can slow plant growth, and it can also allow pests and mould to thrive, which can lead to bud rot.
To get a good airflow going, it’s important to have an open area on one wall of your grow room that allows fresh air in and out. This can be done with a window, a door or simply opening your fan to the outside of your grow room.
Having an open space in your grow room isn’t just about the look; it also means you’ll have a better chance of keeping insects away, says Michael Brown, CEO of Flow Technology. “Stagnant air can attract pests, which can cause disease and mold to grow in your grow room,” he says.
The best way to ensure that your grow room gets plenty of air is to install a proper ventilation system, such as an oscillating fan or a window unit. In addition to keeping your grow room cool, proper airflow can help reduce energy costs and boost productivity.
Humidity
Proper air circulation is one of the most overlooked aspects in a cannabis grow, but it’s vital to keeping plants healthy. Whether you’re growing indoors or outdoors, poor ventilation can cause several issues, such as excess humidity, excessive heat or carbon dioxide levels that drop too low.
High humidity during the flowering stage can cause bud rot, a common and annoying fungus that can ruin your entire crop. In addition, it can cause nutrient burn, which can result in yellow or brownish leaves and damaged buds.
Humidity controls cannabis plants throughout their lifecycle, so it’s important to understand what optimal levels look like. Below are some benchmarks that you should aim for to maximize your yield and ensure you’re doing the best for your plants.
Seedlings and Cuttings require a higher humidity level than mature plants, as it allows them to absorb water through their leaves while their root systems are developing. Ideally, they should be kept at 60-70% RH until the roots are fully developed and capable of extracting nutrients from the substrate.
During the first 3-4 weeks of flowering, you should decrease humidity to 40%. This is important because it can help prevent fungi from flourishing, especially powdery mildew and grey mold.
If you live in a humid climate, you may need to use supplemental dehumidification to keep your growing space’s humidity down. This can be done with a standalone unit or integrated dehumidification that combines humidity and temperature control into one solution.
In addition, it’s best to make sure you have fans around your grow area that are able to move the air in and out of the room. Choosing the right fans can improve airflow and remove moisture, allowing your cannabis to grow healthier and yield more.
Depending on the size of your grow tent and your environment, you may also need a supplemental dehumidification system to help control humidity at all times. Integrated dehumidification systems rely on sophisticated modulating valves to accomplish this task, which makes them more energy-efficient than traditional, on/off units. Regardless of what type of dehumidification you decide to purchase, it’s essential to monitor your RH levels regularly with a hygrometer so you can adjust as needed to provide a consistently dry and consistent growing environment.
Oxygen
A cannabis grow needs good ventilation to provide the necessary carbon dioxide and oxygen that plants require for photosynthesis. Too much of either can stunt the growth of a plant, which is why it’s essential to make sure there’s a steady stream of air flow throughout your grow.
The importance of oxygen in a cannabis grow is more than just the simple fact that it helps keep your bud fresh, though. It’s also crucial for a healthy environment that won’t encourage mould and mildew growth, as well as weak branches and a general lack of vigour.
Oxygen is an odorless gas that has no colour and no taste, and it’s a key component in the biochemical processes that keep your plants healthy. Its atomic number is 8 (O), which makes it one of the most abundant elements in nature and a vital part of our physical survival.
It’s used in rocket propulsion, as a solvent in chemical manufacturing and medical care, as a lubricant in aircraft engines, and for its antioxidant properties. It’s also found naturally in the Earth’s atmosphere and hydrosphere, making it a vital element for all living things on the planet.
During photosynthesis, plants use the oxygen they absorb to create carbohydrates. These carbs are then used as fuel in the plant’s metabolism to produce the nutrients that it needs to grow.
But it’s important not to overdo this. Too much oxygen can irritate the sensitive leaves of cannabis, which can lead to an unpleasant odour and even make it more difficult for the plant to absorb carbon dioxide in the first place.
This is why it’s important to ensure your grow space is ventilated and exhausted regularly, particularly during the flowering phase. You can do this by placing fans in your grow room, and ensuring that the ventilation and exhaust is at a high enough rate to ensure your plant gets the oxygen it needs to thrive.
Ideally you should have a fan or two for each section of your grow room, and be sure to keep the air moving to combat any build-up of aspirated gases, which could stunt your plants’ growth. If you’re growing indoors, you can also add a carbon filter to your grow room, and be sure to check its level regularly.
Carbon Dioxide
One of the most important factors in a successful cannabis grow is proper air circulation. A healthy breathable atmosphere ensures that your plants get the nutrients, water, and light they need to thrive.
A lack of air flow can cause a lot of damage to your growing environment. Plants need a steady supply of fresh air to replenish carbon dioxide and maintain a good level of humidity.
If you’re growing cannabis indoors, it’s especially important to properly ventilate your grow tent. This will ensure that your plants are getting a steady stream of fresh air throughout the day and night, which will allow them to breathe properly.
In addition to this, having proper ventilation can help to prevent certain pests and molds from forming in your grow room. It can also help protect your plants from certain diseases, such as powdery mildew and fungus.
Providing a steady supply of fresh air isn’t hard to do, as long as you keep your ventilation system working well. There are a few different ways to achieve good airflow for your grow room, including installing an intake fan and an exhaust fan.
An intake fan will bring in fresh air from outside and an exhaust fan will remove stale and contaminated air. Both are relatively inexpensive, and you can find them in any hardware store.
It is also a good idea to make sure your ventilation system has air-tight connections between the fan and the ducting. This will ensure that if any odour escapes through the fan, it won’t be able to leak out of the system.
Another benefit of having an exhaust system is that it helps to eliminate the smell of cannabis from your grow tent. This is especially important if you live in an area where it’s illegal to grow cannabis at home.
An exhaust system can be installed in your grow tent, and a carbon filter will eliminate the smell completely. This will help to keep your growing room smelling fresh, and can also prevent it from being discovered by the police.
