Cannabis odor is one of the many things you have to deal with if you have a grow room. Since cannabis cultivation became legal in many countries, environmentalists and anti-cannabis campaigners have consistently complained about the effects of cannabis odor on humans and the ecosystem. These complaints have increased significantly over the years. Some stats records an 87 percent increase since cannabis cultivation became mainstream. In Denver, about 30% of odor complaints are reportedly cannabis-related.
Cannabis is a flower. Essentially the odor is expected. It takes special growing skills to manage this odor Many complaints have described this odor as skunky, flowery, fruity, or pungent. Cannabis grows with different features that produce this odor. During the flowering stage, cannabis produces lush, large, and crystal-like resin-covered buds. In the last six weeks of growth, the terpenes concentration of the plant significantly increases as the trichome becomes more active.
Essential oils from the terpenes are released into the air, giving off a distinct cannabis odor. If you had lived around a growth room with no filtration system, you might know how potent and strong the smell of cannabis buds can be.

Factors that Influence How Cannabis Smells

Although marijuana smell increases during the flowering stage, but your plants do not just start smelling the day, it starts budding. During the growth cycle, the level of smell you get from the plants differs. Many factors and growing conditions are directly responsible for the level of odor you get from your grow room. If you can control these factors, you probably might be able to regulate how your plant smells. The factors include:

smell

1. Temperature

Just as with other plants, marijuana grows better under specified conditions. Many marijuana strains grow better at an ideal temperature range of 21 to 27 degrees Celsius. The prevailing atmospheric conditions and your choice of grow light might affect how hot or how cold your grow room becomes. If the temperature is high, the essential oils vaporize quickly from the plant and are distributed around the grow room. You will want to keep the prevailing conditions in the normal range to avoid this. While doing this, you also must make sure they grow room temperature does not fall below 15 degrees Celsius. This low-temperature range may negatively affect your plant yield and harvest quality.

temperature

2. Humidity

Regulating the relative humidity in your grow room also affects the smell of marijuana. Therefore, you will want to keep the humidity level at the ideal range at every stage of the plant's life. This is especially important during the flowering stage when the plants give off more essential oil. As a rough guide, the recommended humidity range and the corresponding growth stage are highlighted below:

  • Cloning Phase = 70% to 80% humidity
  • Vegetative Phase = 40% to 60% humidity
  • Flowering Phase = 40% to 50% humidity
  • Final Weeks of Flowering Phase = less than 40% humidity

At high humidity levels, marijuana odor can be retained much longer in the grow room. This is why you will want to keep humidity low during the vegetative and flowering phases.

humidity

3. Rate and Direction of Airflow

Air circulation is important for optimum growth rate. In addition to this, the rate and direction of air circulation affect how your grow room smells. Controlling these parameters might help you. If you have more hot and stale air retained in your grow room, the odor of cannabis is reinforced. Your plant might even smell more than you would normally expect. If air direction is poor, such that the entry path of air is the same as the exit path, your marijuana plants will also definitely smell more. Controlling the rate and direction of airflow can also help you with humidity and temperature.

Ways to Control Cannabis Odor in your Grow Room

Controlling cannabis odor is the best way to keep your growing operation secret and not get a complaint from your intrusive neighbors. So, let’s face it. How do you better control the odor without compromising your yield?
In this review, we have compiled the best methods that can probably serve you. Then, all you have to do is consider the cost efficiency and select a method that better fits your growing space.

1. Select a Low-odor Strain

How about you simply avoid the odor through the growth cycle of your plant? Selecting the strains is probably one of the first things you would consider before setting up a cannabis grow room. Your choice of cannabis strains might greatly influence the cost of odor control. Depending on their genetics, different cannabis strains give off different odors. By choosing a strain naturally low in odor, you can easily save money on odor control.
Cannabis strains in this category include Durban Poison, Northern Lights XTRM, Shark’s Breath, Poison Express, and Polar Express. These strains give off little or no smell. Durban Poison is especially popular for its odor-free character. Northern Lights is another low-odor cannabis strain developed specifically for indoor breeding. If you grow one of these varieties, you will get an odor-free environment in your grow space and environment. If you are not limited to a particular cannabis strain, this is the easiest method to solve the odor puzzle.

lemon

2. Consider Odor Neutralizers

If the growing operation is small and restricted to only a few cannabis stands, you might consider odor neutralizers. These products are cheap solutions formulated to suppress the aromas given from the cannabis buds. Odor neutralizers are easy to use and are readily available in agrochemical stores. You will want to better understand the components of these solutions before you select one. Odor neutralizers are so effective that long-term use can change the taste and smell of your cannabis harvest. Making inquiries from the store attendants can help you select a product with little or no effect on your plant taste and smell.
Your best selection should contain components that are biodegradable, non-carcinogenic, and skin-friendly. Some odor neutralizers are formulated as gels and presented in wide-mouthed jars. You can simply open these jars and leave them in the grow room for many weeks. However, you will probably be more successful with odor control during the flowering stage. If you are using a very powerful neutralizer, you might have to leave far away from the grow house. You can also consider odor-neutralizer sprays. They are easy to apply with a fast, almost immediate odor-control action.

odor

3. Carbon Filters

Judging from its popular use, carbon filters are considered the most effective method of controlling cannabis odor. If your grow room is bigger or cultivate many stands in the same space, carbon filters are your choice. It is common to find carbon filters installed as part of the ventilation systems of large cannabis greenhouses. Although carbon filters are expensive, many cannabis farmers still prefer to use them. Also called carbon scrubbers, these equipment contain isolated units of activated charcoal. Carbon filters are installed such that the smell of the budding marijuana is forced through it. In addition, a powerful fan can be used to create a unidirectional airflow, removing the airstream from the growing area through the carbon filters.
One of the smartest ways of creating this flow is by installing the carbon filters in the exhaust system of your grow area. Hot air from the area containing diffused essential oils is forced upwards into the exhaust system. As the air enters the filter and interacts with the activated charcoal units, the filter scrubs the air of marijuana odor. The stream of air released into the atmosphere is clean and free from marijuana odor. Carbon filters continuously help clean and are durable –you only get to replace them after about 12 months.

filter

4. Setting Up Negative Air Pressure

This trick works perfectly for greenhouses and small space grows areas. All you have to do is control the input and output rate of air in your growing area. To create negative pressure, you should have more air entering the growth space and less air leaving it. So, you draw out the odor-laden air, replacing it with clean, fresh air. One of the best ways of setting up a negative pressure is by using a powerful outtake fan, forcing the air out through the exhaust. You will combine this with a less powerful intake face. This setup makes more air leave your grow room and less air entering it. This method is only effective if you have a few marijuana plants in the growing area.

freshair

What You Should Not Use

To control cannabis smell, you will want to avoid ozone generators. In addition to constituting serious health hazards, there are many problems with using ozone generators for cannabis cultivation. They are not as effective as the methods listed here, and they are notoriously terrible for the environment. Fragrance sprays, plug-ins, and air purifiers are also not recommended. These options might serve domestic purposes, but they are useless in controlling cannabis odor.

Final Thought

Marijuana smells are normal and are part of the plant's biology. However, except in naturally low-odor strains, marijuana gives off more smell during the flowering and vegetative stages; installing a carbon filter is considered the most effective and durable method of controlling marijuana odor. Depending on your grow room size, you can also consider other methods detailed in this review. All you have to do is get the equipment and get them properly.