There are many ways to cover the smell of a cannabis grow. It is a very important factor to growing cannabis. If people can smell your plants, they may be discovered. This can result in the plants being stolen, and if you’re growing illegally, it can risk your freedom too!
Covering the smell of your grow is crucial, and it shouldn’t be overlooked. In this guide we will explain some of the best methods used by cannabis growers to hide the smell of their plants indoors and outdoors.
Why Cover the Smell of a Cannabis Grow?
Until you have grown a cannabis plant through its full life cycle, and experienced just how pungent they are during flower, you will not quite know how pungent they are.
A cannabis plant will smell very strong, even in the vegetative stage. But when the flowers are growing, the smell can travel in the air for long distances. It is thick, pungent, and unmistakable! If the wrong person smells it, it won’t be long before they are able to locate your plants.
Cannabis is a very valuable crop, and in some countries it is still illegal to possess and grow. Cops and crooks are always on the hunt for it. To make their job harder and to keep your plants, your property and yourself safe, you need to hide the smell of the grow.
You also need to consider other people. Some people really do not like the smell of cannabis, and you have to respect that. A cannabis plant will be in flower for a couple of months. It is unfair to force people to live around a smell they don’t like for that long. Be a respectful grower, cover the smell!
How to Cover the Smell of a Cannabis Grow Indoors
Covering the smell of a cannabis grow indoors is reasonably easy. Because you are in control of the air flow getting to the plants, you can filter the air before it gets exhausted. This can completely remove the smell from the air.
The most common way to remove the smell from the air is by using a carbon filter. This will be linked up to the extraction in your grow room. With proper extraction and a good quality carbon filter, the smell of your cannabis grow will be completely removed from the exhausted air, leaving no smell at all.
What is a Carbon Filter?
A carbon filter is a metal cylinder that hangs at the top of your grow room or grow tent. It will sometimes have a white cotton sleeve over it. On the outside, there is a metal mesh wall, and it is sealed at the bottom.
Inside of the filter is a big empty space with an inner wall, also made of metal mesh. In between the outer and inner wall is a layer of “activated carbon”. Air passes through this layer of carbon to be filtered before it is exhausted.
Carbon filters are used for many things. From filtering the air in your grow room, to water purification and even used to decaffeinate coffee.
How Does a Carbon Filter Work?
As a substance passes through activated carbon, any contaminants will be absorbed by it. This can be dirt in water, or organic particles in the air. In our case, we are talking about air.
Activated carbon is very porous, and has a large surface area.
One gram of activated carbon has a surface area of 3,000 m2 (32,000 sq ft). This means the air has more surface area to cover before passing through the filter. As a result, more of the organic matter in the air is absorbed by the carbon. This removes the smell.
It is important to buy a high quality trusted carbon filter. Do not buy cheap. This is an accessory that makes the difference between your grow being found or not. Do not cut corners, get a good filter with good activated carbon.
How Long Does a Carbon Filter Last?
After a while, all of the carbon will have absorbed as much as it can and it will not be able to absorb any more. When this happens you need to replace your filter. The amount of time a filter lasts will depend on many things. From how dusty the grow room is, how humid it is, and if you smoke in the room.
The more contaminates the filter has to remove from the air, the less time it will last.
A good rule of thumb is change the filter every 2 grows! You need to make sure the smell of your grow is covered 100% of the time. A failed filter will get your crop discovered!
How to Use a Carbon Filter
A carbon filter will be linked up to your extractor fan. If you are using a 5 inch extractor, you should use a 5 inch carbon filter. You will use ducting to connect the filter to your fan.
The best way to cover the smell of a cannabis grow, is to hang the carbon filter at the top of your grow room. The air is then sucked through the filter using your extraction and vented outside.
It is good to have the extraction sucking the air through, as this will create negative pressure and prevent smells leaking out of the grow room. But some growers will have the air blowing through the filter on the other end of the extractor.
Which Way Should Air Flow Through a Carbon Filter?
There are two ways air can pass through your carbon filter. It can be blown through, or sucked through. You can use either one, as long as all of the air from the grow room passes through the filter before being exhausted. No matter which way you choose, you need to ensure you have negative pressure in your room.
What is Negative Pressure?
To make sure no air escapes your grow room without being filtered, you need to have negative pressure in the room. This is done simply by extracting more air out of it, than is going into it. Doing this will create less air pressure in the grow room, so air is always sucked in.
What is Positive Pressure?
Positive pressure is when you blow more air into a room that can escape it. This means air will push its way out anywhere it can, through zips, seams and vents. This air will not be filtered and will smell. Positive pressure is usually used in the grow room to keep bugs and dust away.
Is it Better to Suck or Blow Air Through a Carbon Filter?
For best results, you should hang your filter at the top of your grow room, and have your extraction SUCK the air through it. This is the best way to cover the smell of a cannabis grow indoors. Not only will this give you negative pressure in the grow room, but it also gives you the opportunity to properly vent the air outside.
If you choose to blow the air through the filter, then the filter should be on the other end of the extractor, not in the grow room! All air must pass through the filter. The problem with this method is you will need to ensure the room the air is exhausting into is well ventilated.
Carbon filters might remove the smell, but they do not remove the moisture and humidity. If not properly vented this moisture can build up and cause mould in lofts and wall cavities.
For best results, use a carbon filter in your grow room, and suck the air through it. Then exhaust that air straight outside.
Using Perfumes and Fragrances to Cover the Smell of a Cannabis Grow
Using perfumes and fragrances to cover the smell of a cannabis grow is not advised. Though it can be done in the early days of veg, it should not be done during the flowering process!
The particles from perfumes and fragrances will travel in the air. They will be drawn into your grow room. If your plants are in flower at this point, those particles will land on your buds.
Not only will this taint the smell and flavour of your buds, but it could be toxic too! Do not use any scented items to cover the smell of a cannabis grow. Use a carbon filter with suitable extraction.
Covering the Smell of a Cannabis Grow Outdoors
Covering the smell of cannabis grown outdoors is not easy! You can not control the flow of air and filter it like when growing indoors. Instead you have to try and cover the smell by growing other plants that are also very pungent.
Though the smell of a flowering cannabis plant is very distinct, you can try to cover it by using companion plants. But you can never cover the smell fully. So try to start your grow somewhere where people are not likely to go. If no one is around, then no one will smell it.
To help you cover the smell of an outdoor cannabis grow, here is a list of plants that can help cover the smell of outdoors cannabis plants. This is known as companion planting.
Thyme is a pungent herb that can help mask the smell of cannabis plants. Plant some English Thyme around your plants to cover the smell. You can also use the Thyme for cooking once it has grown.
Mint is another plant you can use for companion planting. We all know the smell of mint, and it can be used in the kitchen too. It can also be a great deterrent for pests!
Rosemary is fragrant, and it also grows reasonably tall. You shouldn’t plant the rosemary too close to your cannabis plant, as it may shade it in early growth.
Basil is a common cooking ingredient, and it is very easy to grow. Planting some near your cannabis plant can cover the smell of your grow.
If there is anything that can cover the smell of an outdoor cannabis grow, lavender is it. Because of the strong smell insects may go to the lavender instead of your cannabis plant too.
A great companion plant that deters pests and has many uses! Simply plant some near your cannabis grow and it will help cover the smell and keep insects away.
Covering the smell of a cannabis grow is much easier to do indoors than outdoors. But that doesn’t mean its not possible to do outdoors either. By using companion plants and planting your cannabis plant in a good spot, there is very little chance of some one smelling it.
When you grow indoors, you must use a carbon filter. Your home will stink of cannabis more than you realise if you do not.
Remember the three rules of growing, don’t tell, don’t sell, and cover the smell! Your security and safety relies on it. Make sure the smell is covered.