Tips and Tricks to Prevent Cannabis Odor

marijuana card

Tips and Tricks to Prevent Cannabis Odor

By Robert Bergman,

smellMarijuana has an undeniably, strong, unique smell that anyone can recognize. How many times have you been out and suddenly you were hit with it? I am pretty sure you were 100% aware of what it was you were smelling.

This odor is appealing to some, however, it can completely blow up your spot in the wrong way if the wrong people catch a hint of it coming from your grow room.

With each passing day,  marijuana is becoming more and more popular worldwide as people begin discovering its medical benefits or enjoy it for a real high. We now have more people growing marijuana indoors than ever before so there is a pressing need to help growers learn to cover up the odor these plants give off. The smell while growing marijuana is what makes the practice so risky since the last thing you need is this to get the attention of people living in your area.

Delta Extrax

A grow room is bound to kick up a serious amount of potent marijuana odor, so attempting to grow without knowing how to properly deal with heavy odors could cause you to end up being a target for robbery or worse getting in trouble with the law. However, masking the smell can be a challenge. Your approach varies based on the size of your grow space. With a small grow space that has only 1 or 2 plants, it is possible to mask the smell much easier. This is definitely not the case with big grow areas because you literally need to scrub the air.

Odor is a big deal. So, if you are planning to grow indoors, this article will be informative and teach you how to neutralize odors the best way.

Great ways to prevent marijuana odors

Great ways to prevent cannabis odors

Now that we are clear about the fact that marijuana odor is the main reason for growers getting caught, we need to explore the means to prevent this from happening. You should be able to enjoy a good high without your neighbors putting the obvious pieces together that will lead to you getting exposed. We all know that people love to run their mouth about who is doing what so let’s give them less to talk about, especially when it something as sensitive as growing marijuana.

So, not only do you want to ensure your grow space isn’t giving you away by emitting a potent smell, you also want to be sure you are not talking about it.

Here are the causes of potent marijuana smells and how you solve this problem:

  1. Your vent fan is lacking a vacuum

Fans are necessary for your grow space because they can be used to remove the air from the environment. Take the time to properly position the fan so that it functions as a vacuum in your grow space. Basically, this is the way you will know that all the air is only leaving through a filter.

One way you can know that you created an adequate vacuum is by placing a thread in the opening of the grow space and keeping the door open just a little bit. When you notice the thread being sucked back into the room, then you now have a good vacuum. With any other results, you know not that the cannabis smell is going to escape your grow room through cracks and holes in the space.

Download my free marijuana grow guide at this link for more growing tips

It is e ssential that your space has the right amount of ventilation at all times.

For a more detailed breakdown, you will want to divide the number of lamps by the number of watts by 2 which will equal the air outlet. For example: for 5 x 600 watt you need 1500m2 outlet and 750m2 inlet. When you multiply 5 x 600, you get 3000 then divide it y 2 which equals 1500m2 air inlet. Combine the vent fans to one controller to make sure you don’t end up activating just the air inlet. When you only activate the air inlet, it will result in too much pressure based on the conditions in the various parts of your marijuana grow space.

  1. Not having the right filter
  2. You don’t want a vent fan that is too small because your crop could easily be discovered by nosy neighbors. For example, a vent fan that measures 1500m3 will need a filter that is adjusted for 1500m3. For the absolute best results, change your filter to be 20% more volume than the vent fan. Filters have active carbon that will neutralize negatively charged odor ions.

Filters that are too small result in the vent fan forcing air through too fast so that the air doesn’t filter properly. Filters should never be used more than a year because it will get to a point that it no longer works right.
While you have to ability to switch out the carbon filters on your own, this can get tricky since it requires professional equipment such as a vibrating plate to spread the carbon in equal proportions. Don’t take the chance – just get yourself a brand new filter.

  1. Exhaust leaks

It is easy for a single leak to go unnoticed. Something like this could seem small, but it could be the reason for a very potent marijuana smell being released.

If you have one of those filters that are connected to a vent fan with a hose, then you’d want to make sure it is properly fixed with clamps. Always check the hose to make sure there are no holes. Insulated tubes require particular attention due to the inner aluminum tube having small holes in it. Attach the inner tube to the flange first since it connects much easier. Then you can connect the outer part of the hose with a clamp and secure it to the box.

Systems that help mask the smell of indoor marijuana growing spaces

Systems that help mask the smell of indoor cannabis growing spaces

There are systems that effectively mask the smell of marijuana and even eradicate it altogether. T hey are available with different features and at different prices.

The most popular ways to remove cannabis odors are:

  1. Odor neutralizers
  2. Air purifiers
  3. Carbon scrubbers

Odor neutralizers

These are used to cover up marijuana odors. Because odor neutralizers are so potent, they can actually affect the taste of buds after some time.  We never suggest putting these in your grow room while the plants are flowering. But, you can use odor neutralizers that have a very potent aroma to stop smells from spreading outside the space. However, if you are interested in scrubbing the odor from the air, this is not the way to get that done.

Good luck if you plan on using wall plug-ins and sprays to deal with cannabis odors because the odds that they will mask the smell for long periods of time is very slim. Even more, these products have an adverse side effect as they could potentially mess up the natural smell of marijuana plants.

You will need an odor neutralizer that is capable of being consistent throughout your plant’s various growth cycles since the plant never stops emitting its smell while growing. Here are some solutions to this problem for those cultivating in a small grow room.

Ona products

Ona gels to prevent cannabis ordor
Ona products are a great solution that  have been on the market since 1995. They work well hydro grow systems.  Ona is available as a gel, block, and mist product. Initially, both Ona Gel and Blocks were created with the intent to manage the foul odor inside of sewage facilities. Once people began to realize just how well these products reduce neutralize strong odors in general, they became more readily available.

  • Ona gels

Ona gel is available as small gel cubes that reduce unpleasant odors and replace it with a more preferred scent. These little cubes will successfully do their job until they are completely dried out. It is common to put them in the air vents which is a great way to make sure air is always filled with an enjoyable scent. There are multiple scents to choose from.

Ona blocks

These are not all the different from Ona gels except they are actually 170-gram tablets that you leave out in the grow room.

  • Ona mist

Ona mist is a spray that reduces smells very quickly and can be used for this purpose in your car and living space. As an extra bonus, this product is 100% organic and can be trusted to use around children, food and pets.

  • More about Ona products

While these products are great at neutralizing odors fast, work well in small grow rooms and are simple to use, they do not last long. You will have to purchase new ones just about every 3 to 4 weeks. Various testing has proven that Ona Gel is best for masking marijuana odors so long as you do not have many plants you are growing in the space. With just 1 or 2 tablets situated outside of the grow space you can effectively cover up the scent.

Even though these products are great, we warn you not to put these inside near plants that are flowering.  Ona products could mess up the smell of your marijuana buds if place in the same space as the growing plant, hence the warning. Putting this product in your living room, for instance, is good enough to mask the smell from anyone who comes over. Again, remember that Ona products are only to be used outside of your grow room.

The Neutralizer

The Neutralizer to prevent cannabis odor
Another great product that comes highly recommended is The Neutralizer which has actually won awards in Europe for its effectiveness. It consists of essential oils that neutralize smells and replaces them with an enjoyable scent. It actually functions similar to regular plug-ins you buy at the store. The steps are simple and only require you to put the cartridge in place and plug it in.

Again, this is another product that is good for small grow rooms and can last as long as 5 to 6 weeks.

For very small spaces, you can purchase the condensed form which also lasts the same amount of time. And with both of them, you can get interchangeable cartridges.


Vaportronic to prevent cannabis odor
Vaportronic products come in discs of either 6 or 12 grams that consist of Neutrox Gama. The cool thing is you can program these discs to operate at different times with up to 5 discs at a time. These are called EZ disks which require a D battery for you to use it.

These discs can last you almost two months and are perfect for small grow rooms as well. The scent they give off is a lovely pine or eucalyptus smell.

Air purifiers

Air purifiers to help with cannabis odor

Who doesn’t like to have fresh, clean air to breathe in their environment? A ir purifiers are easy to find, and many claim to remove unwanted smells via a filter.

While air purifiers may be great to rid your home and overall environment of unpleasant odors, there are questions about how effective they are for eliminating potent marijuana smells in your grow space. Well, as you may have guessed, the answer is not very effective.

There are good air purifiers on the market that will get rid of certain odors in the air, but this just won’t cut it for indoor marijuana growing. While it may remove some of the odors, you will end up needing something stronger to get the job done right. Now, some air purifiers do help remove bad odors from the air. However, they are only marginally effective. They simply are not potent enough to pull every smell from a grow room. Therefore,  we do not recommend only using an air purifier to get rid of odors in your grow room.

You are better off sticking to air purifiers for less potent scents and going with the big boys for that cannabis scent.

Carbon filters

Carbon filters to prevent cannabis odor

Of all the products available to eradicate odors, carbon filters, also known as ‘carbon scrubbers,’ are by far one of the more desirable options for eliminating harsh odors when doing indoor marijuana growing. These are highly effective even when growing strains that are known to let off the strongest odor. Carbon filters literally scrub the odor from the air and neutralize all smells that come through.

When you want to neutralize the air leaving from your exhaust carbon filters are the way to go. Carbon filters are excellent for making sure there are no chances of a marijuana scent exiting the window or some other exit point and into your neighborhood. These are a sure way to keep your marijuana growing private and prevent you from getting into any trouble.

When using carbon filters, you are going to need a tubular air extractor that has the right efficiency for your particular grow room. When the air is removed from the grow space it goes through the filter that is full of little small active carbon bullets, then leaves out without any smell. Carbon filters are different from the other systems because it does give off a fragrance and will only remove all odors from the space. These can be purchased in various sizes so you can select one that is perfect for your particular space.

Carbon filters are very reliable, simple to maintain after you get it set up, and they will last you a long time!

They use activated carbon to consume the odor from the air that is forced through the filter. You have to actually create a way for the nasty cannabis odor to be pushed into the filter by using a fan which will do this for you. To accomplish this goal, we suggest you get a carbon filter as part of your exhaust system that will contain an exhaust fan which will force the air out of your space. When the warm air is forced from the area where your plants are, the carbon filter will scrub all smells from the air at the same time.

Installing your carbon filter
The first thing you need to consider is how big your exhaust is. You will find that several air-cooled cannabis grow lights have a 6-inch exhaust hole. If you are growingin a small space, then you will need to get all your stuff in 6”.

The reason you want to get a 6” fan is because they have the ability to clear the air from just about any small grow space. Do not settle for a 4-inch fan because you will be sorely disappointed since they are not strong enough for a 6-inch carbon filter and to make it worse they won’t fit the regular air-cooled grow lights.

You only want to purchase 8-inch filters for commercial facilities that need very strong fans, and you will never be able to connect this to your standard grow lights.

Next, you should make sure the CFM rating matches the fan and carbon filter. The carbon filter’s CFM rating should be exactly like or even higher than the one you see listed on the fan. By doing this, you will have the best results and the carbon filter will only absorb the amount of air it can to scrub the odor out.

After you have considered these two things, install the fan and filter into your exhaust system. Pay very close attention to the provided instructions when installing your filter and fan. You can find many examples that will clearly show you how to properly set up your carbon filter in your exhaust system. When you have your carbon filter situated towards the back of the exhaust system, it will reduce the possibility of marijuana odors leaving the space during the flowering phase – when it is likely to be letting off the most potent scents.

Stay away from ozone generators

Stay away from ozone generators to prevent cannabis odor

When talking about preventing marijuana odors, we must mention ozone generators because many are trying this method, but we have some warnings for you.

These are actually quite new in terms of systems used to neutralize odors in marijuana grow rooms. Ozone generators are said to eliminate smells, freshen up the air and destroy mold. Yes, you will find many marijuana growers giving praise to ozone generators for getting rid of odors, but we just disagree with using these for marijuana growing.

So, I know you are wondering why we advise against using ozone generators. Ozone generators are terrible for the atmosphere to the point that they are actually illegal in certain states. Now this should say something! Not only are ozone generators illegal in some places, but they are also not good for you!

Below you will find some links that will lead you to more information about ozone generators and why they aren’t good for you. Some organizations that have suggested against them include:

Some growers swear you can safely use ozone in your grow room by venting it from the space ensuring that it only gets into the exhaust. We say why take the risk of using ozone when a carbon filter works just as good without the possibility of causing health problems.  You and your family are safer and better off without it.

1 Comment

  • ivan
    January 22, 2017

    Hi can u use lumps of raw organic charcoal in a bucket with lots of holes drilled into it ,and have a few in the room will this absorb the smells ?

Post a Comment