Top Tips How to Fight Cannabis Grow Room Scents, Aromas, and Smells

When growing in an urban environment, considerations need to be taken to account for other people and families living in close proximity. One of these considerations is smell.

If you’re a grower you already know about the scents your garden gives off all year round. Some are welcome, some are… less than invited into the nostrils of our neighbors. No matter what the scent or how strong, aromas in the grow room and the garden are something growers have to deal with during every grow cycle.

Fortunately, there are a range of techniques that can be implemented to mitigate this odiferous opportunity which can be implemented in any sized indoor grow. If used in combination with one another, many of these techniques are capable of completely removing all odors in a cannabis grown room, leaving you to propagate worry-free.

Where Does The Smell Come From?

Cannabis plants that are in their vegetative stage sustain a very low scent because they haven’t produced terpenes— the molecules responsible for the aromatic properties of a marijuana plant.

A weed plant will develop trichomes when it transitions to the blooming phase and starts to produce flowering nodes.

The trichomes are the molecule factories that create plenty of aromatic compounds.

What Strengthens Odor In A Marijuana Grow Room?

If left uncontrolled, the stench will remain in the air, eventually permeating an entire grow space.

What is a Scent?

A scent is what we smell when we inhale a certain concentration of “odorant molecules” that react with receptor cells in our noses. These molecules are only found in volatile organisms, which are organisms that can easily be turned in to gas. That’s why things that break down easily give off scents, versus materials like steel, rocks, and minerals that do not have a scent.

No matter what the scent or how strong, aromas in the grow room and the garden are something growers have to deal with during every grow cycle.

Whether it’s your blooming flowers, the humid air, or your soil, your garden’s full of scents that you’ll face. Because we all love a great harvest, but not everyone appreciates the smells that come with them.

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Humidity Levels And Temperature

High humidity and temperature can prolong cannabis scent in a grow room. Therefore, the first step to consider is whether you’ve set the proper temperature and relative humidity.

Certain strains may have a particular need, but these are the recommended humidity levels in various phases of marijuana growth.

  • 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

As your weed plants transition and grow, you must be mindful about controlling temperature and humidity. You can do this by using air conditioners or dehumidifiers.

Proper Air Circulation Is Important

Proper air circulation helps maintain temperature and cannabis odor low in a grow space. Additionally, it can recycle used CO2 out of your grow space.

Thus, ensuring your grow space has the right air circulation keeps the appropriate temperature and relative humidity.

Grow lights emit heat in variable quantities. Hotter systems like ceramic metal halides (CMH) and high intensity discharge (HID) might find it more difficult to suppress heat.

Yet, smaller lighting systems like Light Emitting Diodes (LED) and compact fluorescents have their own struggles as well.

All growing lighting systems can discharge hazardously high temperatures if there isn’t suitable air circulation and ventilation.

Generally, air should be able to circulate around a grow space every few minutes during the vegetative stage and every minute during the blooming stage.

The most convenient way to guarantee air circulation is to install either standing or oscillating fans.

When fans are paired with ducted intake and exhaust fans, it becomes easier for the air to move around, taking the smell out with them.

Odor Absorbing Gels May Help

Odor becomes much more difficult to manage in the final six weeks of a cannabis plant’s lifecycle. This is the stage where trichomes are producing their highest concentration of terpenes, and your garden is certainly going to try to show them off to you (and perhaps to your neighbors). Air circulation and ventilation aside, there comes a time when all of the air in your living space will contain traces of your garden’s fresh floral smell.

At this point, you may want to consider more rigorous odor management practices such as odor absorbing gels. These products work by attaching to odors and replacing them with other, more appealing scents. Keep in mind that odor gels do not eliminate odors, but simply mask them. Odor eliminating sprays help a bunch as well, but they operate under the same principle, not actually removing odors, but simply making them more pleasant.

Try Activated Carbon Filters

If you want to destroy 90% of the odors in your garden on contact, you’ll want an activated carbon filter. Also known as “carbon scrubbers” for their ability to literally scrub contaminants out of the air, these devices employ activated and highly ionized carbon to attract particulates from the air. Dust, hair, mold spores, and volatile organic compounds responsible for carrying odors are all trapped either in a pre-filter or by the ionized carbon molecules inside of the filter’s main cylinder.

Filters in a flowering garden can serve one of two purposes. With CO2 supplemented air or in rooms very high in CO2, filters can be placed on the floor to recycle scrubbed air back into your space. However, most rooms utilize carbon filters with an exhaust, a great way to not only redistribute heat, but stale, depleted air as well.

Here’s A Fun Fact

Carbon scrubbed environments can get the airborne bacterial counts in your marijuana grow space from a whopping 10,000 parts per million to as low as 30 parts per million.

Furthermore, using a carbon filter to control odor in a marijuana grow room is the most environmentally friendly technique.

Note that carbon filters may come 4 to 12 inches in circumference. To determine what carbon filter size you require, you must first identify the cubic feet per minute of your marijuana grow space.

To measure this, simply multiply the length, width, and height.

For instance, you have a 4×4 grow space:

4 x 4 x 6.5 = 104 CFM

Here’s a table identifying the appropriate carbon filter sizes with the average cubic feet per minute (CFM).

  • 4-inch carbon filter = 260 CFM
  • 6-inch carbon filter = 530 CFM
  • 8-inch carbon filter = 780 CFM
  • 10-inch carbon filter = 860 CFM
  • 12-inch carbon filter = 1765 CFM

Can Air Purifiers Remove Odor In A Marijuana Grow Room?

Well, air purifiers won’t have the power to do so.

We know how air purifiers work well in removing dust and allergies from the air circulating in our homes.

However, they aren’t potent enough to cover the strong smell of flowering marijuana.

Remember to always be courteous when growing indoor cannabis and understand that the odors associated with this hobby are not equally pleasing to everyone.

A temperature controlled and fully ventilated marijuana grow room equipped with a carbon filter exhaust and fans are able of removing almost 100% of the smell in your cannabis grow room.

Employing any one or combination of these systems will not cost you too much out of pocket, and the investment at the end of the day should pay itself over in the silence of your unhindered friends, family, and neighbors.

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