If you are new to growing marijuana, or have been trying to grow it, but have been unsuccessful, this article is for you. Proper Air circulation in marijuana grow rooms is an important part of the process. If there is improper circulation, your plant growth may stunt, you may have weak branches which won’t hold the weight of heavy buds, and you might end up with a mildew or bug problem. All of these issues can be combated with the right size fans, placed appropriately.

How Plants Grow

Marijuana plants, like all plants thrive off of carbon dioxide (CO2). The carbon dioxide that is in the air, is absorbed by plants and it helps them to grow thick and strong. Without enough CO2, plants will not thrive; staying limp or brittle. Picture an elderly man with oxygen and then take the oxygen away, he will not function as well. That is your marijuana plant without adequate CO2; a frail old man.

Air circulation is important to ensure that fresh air is being brought into your growing room or tent. If the air is still, it gets stagnant and it will also be void of crucial CO2 which will make your plants suffer.

To ensure that your plants stay strong, make sure that you are bringing fresh air in with proper ventilation and air circulation.

How Air Circulation Benefits Your Plants

Marijuana that is grown outside grows big and strong because it gets plenty of air. Again, air has CO2 and that helps the plant to thrive.  

When growing outside is not an option, and you are using a grow tent, you need to recreate the outdoors with lights and fresh air. While lights are a discussion for another time, fresh air can be vented in and circulated with fans.

The best way to see that your plants are getting the right amount of air is that they should gently rustle. Think about the way the leaves on a tree blow in the breeze. This is what you want. It is especially important in the canopy, or the tops of the plants. Anything more, and it can be damaging to the plant, anything less, and they aren’t getting the proper amount of CO2 exchange.

Additionally, plants need proper air at the base. This will ensure that the plants don’t stay damp for too long, getting mildewed or moldy. It also keeps bugs away. Incorporating fans that will hit the lower parts of your plants is just as important as fans that circulate air and rustle the canopy.

Types of Fans

Fans come is a vast variety of types and sizes. Depending on the size of the tent you have, and the type of fan you are using, will determine how many fans you will need.

Ceiling Fan

In most scenarios one ceiling fan should suffice, for a beginner’s tent.

Oscillating Stand Fan

Oscillating fans are great because they can re-direct the air over multiple plants. Also, because you can adjust the height, you can direct them to hit both the canopy and the base of the plants at the same time.

Oscillating fans come in sizes ranging from 8” to 30.”

Tower Fans

Tower fans are ideal because they move the air and eliminate any unnecessary noise. The tower design allows air to be more efficiently distributed throughout the room.

Clip on Fans

Clip on fans are also great for smaller tents. If you have a larger set up, several clip-on fans would be beneficial. They have a similar effect as oscillating fans; they can be redirected to hit the most plants possible.

How to Safely Install a Tent Fan

Always use a GFCI outlet. When you have fans running in an area where water is being used or sprayed, having a safety outlet is important.

Also, take care to where you hang or place the fan. If water is being sprayed above them, it can get into the blade area and burn out the motor.

Air circulation is extremely important to growing a strong and healthy crop. If you have good air, your plants will get the necessary CO2 and flourish. This will produce a strong plant with strong branches that can support buds. And mildew will not be as much of a problem.

Make sure you also read our article about the best in-line fans for grow rooms.