5 Tips for Controlling Odor in Your Cannabis Garden

Published on October 24, 2017 · Last updated July 28, 2020

The pungent aroma of living cannabis is something to be celebrated by many growers, but unfortunately the smell can also draw undesired attention to a garden. Thankfully, odor control techniques have been developed for growers seeking personal security or to respect less enthusiastic neighbors. Here, we’ll explore some of the most popular and effective methods available.

1. Install Carbon Filters

Carbon filters are the go-to for odor control in your standard grow room. Using activated carbon, they can capture a large number of impurities in the air including odors. Activated carbon covers an exceptionally high surface area due to its porous and cavernous structure.

Carbon filters come in all shapes and sizes, and there’s one important rating to consider with fans and filters. CFM (cubic feet per minute) refers to how much cubic feet of air will pass through the filter and fan per minute. Because the filter and fan work together, they need to be compatible. A good way to guarantee your filter is big enough is to make sure it has a higher CFM rating than your fan. This also ensures that your fan will not be strained by a filter with a lower CFM rating.

When selecting your carbon filter and fan, make sure you’re able to move all the air through the room every five minutes. For example, if you have a grow room that has a square footage of 500 square feet, then choose a fan and filter that can handle 100 CFM to achieve 500 square feet in five minutes, successfully replacing the air in your grow room.

2. Use Negative Space Air Pressure

This technique generally goes hand-in-hand with the use of carbon filters and high-velocity fans. Negative space air pressure is achieved when the power of the outtake fan is strong enough to create negative pressure in your grow room. The negative pressure ensures that air is being pulled through any cracks in your grow room into the outtake fan instead of the air leaking outwards through the cracks.

This method will keep the odor from penetrating into other rooms in the home/building, but you’ll need to attach a carbon filter to the outtake fan to ensure that both the surrounding area and outtake air are odor-free.

3. Consider Odor Neutralizers

Odor neutralizers are a simple way to control the odor of your garden. In their more complex form, these neutralizers consist of gels and oils that bind with cannabis’ aromatic terpenes and remove them from the air.

Because they seek out and bind to terpenes, these products are not for use within your grow room. Instead, they should be used to improve the smell of rooms that are being affected by the grow room that is nearby. If you use these products in your grow room, you will alter the taste and smell of your product permanently.

For small gardens, lower-end odor neutralizers consist of products that simply mask the smell of cannabis plants, such as candles or car fresheners. They aren’t ideal, but they’re an inexpensive and easy way to dampen the aroma outside a small garden.

What are cannabis terpenes and what do they do?

4. Air Filters Alone Don’t Control Odor Well

Air filters are set up to work like carbon filters, but they’re generally used to capture larger molecules like mold or dust. Cannabis terpenes produced from cannabis plants are quite small and often will slip through most air filters. High-end HEPA filters will capture more terpenes but are very costly in comparison to carbon filters. While air filters will help keep the air in your garden space cleaner, they are not recommended as your sole source of odor control.

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5. Check Your Equipment

It may sound obvious, but make sure your odor control system is running correctly if you feel your garden is too pungent. All the air filters and carbon filters in the world don’t make a difference if your ducting isn’t secured properly or the power to run your system is not being generated. Routinely check your ducting for holes or issues with your seals. Check the exhaust from your outtake fan and make sure no odor is coming out to ensure your carbon filter does not need to be replaced.

Do you have additional tips for maintaining a subtle garden? Leave a comment below with your advice or questions!

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Trevor Hennings
Trevor Hennings
Trevor is a freelance writer and photographer. He has spent years in California working in the cannabis industry.
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