When growing cannabis, there are many things we have in mind: Are our plants healthy? Is the amount of fertilization dialed in correctly? What are the final yields going to be like? Especially for novice growers, and people who want to try indoor growing for the first time, it's crucial to understand that there are a few basic things that should get our full attention, before thinking about heavy yields and high-quality buds.

By far one of the most important thing when growing cannabis indoors is odor control, meaning the reduction of the delightful but risky smell that mature cannabis blossoms emit during flowering.

WHY IS ODOR CONTROL SO IMPORTANT?

In many countries, it's still necessary for hobby growers to keep their plants a well-hidden secret. A house or apartment that constantly smells like a large plantation right before harvest draws a lot of attention to it. Here are three main reasons why it's necessary to control the smell of your plants:

1. In some countries law enforcement might enforce the local cannabis laws.
2. You might get confronted with Neighbors who feel disturbed by the smell.
3. People you don't know could potentially smell your plants, and have the bright idea to steal them.

Smell control in the cannabis grow room

Install Carbon Filters

Carbon filters are capable of 'scrubbing' contaminants out of the air by emitting activated and highly ionized carbon to draw particulates from the air.

As a result, volatile organic compounds such as mold spores, dust, and hair that carry odor become confined in a pre-filter.

Sometimes, ionized carbon molecules inside the filter's main cylinder trap those compounds.

Once the filter cleans the air, you are left with fresh air that doesn't harbor odor molecules.

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 4x4 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 with a 260 CFM max
• ​6 inch carbon filter with a 530 CFM max
• ​​8 inch carbon filter with a 780 CFM max
• ​10 inch carbon filter with a 860 CFM max
• ​​12 inch carbon filter with a 1765 CFM max

Inline Fans are essential when using a carbon filter.

For the proper fan to clean the room or tent it will be determined by the cubic feet per minute.

The same as the filter which makes it pretty easy to select.Inline fans also come in various sizes, price ranges, and noise levels.Usually the lower end is noisier than a more expensive one.You will also have to determine the size of fan you require to match it up with your filter.

They are all measured in cubic feet per minute the same as the carbon filters above so use this simple math equation to figure it out

Measure the length of growing space the width and height then multiply them, for example; a 4x4 grow tent.
4x4x6.5=104 CFM

• 4 inch inline fan with a 260 CFM max
• ​6 inch inline fan with a 530 CFM max
• ​8 inch inline fan with a 780 CFM max
• ​10 inch inline fan with a 860 CFM max
• ​12 inch inline fan with a 1765 CFM max

Note that inline fans come in different sizes and a range of prices. Also, the noisier models are typically the cheaper ones.

Fan diameters are usually 4, 6, and 8 inches. A 6-inch diameter fan is the most used.

Furthermore, you'll have to connect outside ducting to the inline fan so hot and stagnant air can flow away, bringing the scent with it.

Don't forget to place the fan properly so it can function as a vacuum inside your weed grow space. In this way, you'll know if the air is only leaving through the filter.

Anti-odour systems for cannabis grow rooms

We can find many anti-odour systems that either camouflage or eliminate the smell of the plants. There is a wide range of products that differ greatly in price and features. What follows is a brief over-view of these products.

Ona, anti-odour gels and diffusers

Ona is a Canadian company that has made anti-odour products since 1995, for hydroponic set-ups, processing plants and drainage systems. They offer many products, the best of which are below:

• Ona Mist is a spray that neutralizes odour molecules rapidly. It is perfect for eliminating smells at home or in the car in just a few seconds. It has organic ingredients and is safe for children, animals and around food.
• Ona Gel is made up of small cubes of gel that eliminate unwanted smells, leaving a pleasant scent in the air. It is used by simply opening the box (or by removing a small quantity of cubes) and they will be effective until they are dry. Many growers place small quantities of these cubes in the air vents ensuring that the air expulsed smells pleasantly. They come in various different odours, each to their own. It can be used together with the automatic dispenser, Ona Breeze, to improve efficiency.
• Ona Block is similar to Ona Gel but in this case they are solid 170g tablets that can be left in a room or the desired space.

The Neutralizer

The Neutralizer is an award winning product (Best European Product 2013, European Product Awards) and works like any other plug-in air freshener or mosquito plug. To use it, just insert the cartridge and plug it in. The liquid is made up of essential oils and neutralizes odours in the vicinity and leaves behind a pleasant aroma.

It works in spaces up to 375m3 and will last for 5 to 6 weeks when working 24 hours a day which makes it an interesting option for freeing ourselves of undesired smells. The Neutralizer also comes in a compact version that works in spaces up to 20m3 and will last as long as the larger model. Replaceable cartridges are available for both versions.

Vaportronic

The Vaportronic by Vaportec is a small dispenser that uses anti-odour discs of 6 or 12g that are impregnated with the active material Neutrox Gama. It can be programmed to work at different time periods and can be loaded with up to 5 anti-odour discs, called EZ disks. It needs a battery, type D, to work.

The anti-odour discs last about 50 days and will work effectively in spaces up to 60m3, leaving a smell of eucalyptus or pine.

Air Purifiers (Air Filters)

We all love the idea of having pure air to breathe. Many air purifiers come with the claim of reducing smells, usually by means of a filter. Do these work to get rid of smells in a marijuana grow room?

Not really.

It is true that some air purifiers do help remove some smells from the air. However, these are not strong enough to pull all the smells from a grow room. These are only marginally effective.

Therefore, while air purifiers may be a good choice for other reasons, I do not recommend getting one just to try to get rid of smells in your grow room.

Key Takeaways

While growing indoor marijuana brings you joy, remember that the aroma might not be pleasing to everyone, especially to your close proximity.

Using one of our suggested methods or combining some of them are investments worth taking. The units we've introduced are, in fact, essential to indoor gardening.

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.

Likewise, creating a good airflow across your growing space keep humidity levels and temperature stable.

Keep in mind that removing all air particulates results in unhealthy air in your grow room. Hence, the secret is to control the odor.

Combat that smell using these proven techniques and don't let the odor stop you from producing quality marijuana in a grow space!