How Long Do Carbon Filters Last in a Grow Tent?

Growers could be sometime confused about how long carbon filters last in a grow tent and how often we change them. After all, the last thing any grower would want is smell leaking out of the grow tent, and eventually, out of the house.

Manufacturers state that 1-2 years is the average lifespan of any carbon filter operating in a grow tent continuously 24/7. According to several critical factors that impact the lifespan of a carbon filter in a grow tent, the lifespan could be extended by additional 2 years.

I found it irritating that there are some critical old-school tricks that many newbie growers are not aware of.

Manufacturers tend to give grow tent carbon filters a set lifespan period. However, there are a lot of variables that control such lifespan periods. Moreover, certain tips could be used that I found almost nobody talking about that will potentially boost the efficiency of any grow tent carbon filter and extend its lifespan.

This post will be a sequential step-by-step guide to know everything about when your grow tent carbon filter needs replacement and how to use some tips and tricks to get around replacing it.

Factors Affecting How Long A Grow Tent Carbon Filter Last

Before diving into the critical information, you need to get a brief summary on what are the variables that affect a to grow tent carbon filter.

1-Quality Of Activated Carbon

Activated carbon filters are designed to remove harmful toxins and chemicals from the air, and they play an important role in how long a grow tent carbon filter would last.

Poor-quality activated carbon will not adsorb as many odors as high-quality activated carbon, and it will also lose its efficiency more quickly.

It is important to select a high-quality activated carbon filter for your grow tent carbon filtration system. This will ensure that the grow tent carbon filter is working as it should, and that it is able to remove any produced odor and prevent it from leaking outside of the grow tent.

When it comes to choosing an activated carbon filter with high adsorption properties, there is really nothing better than Australian-certified virgin carbon.

IAV RatingAdsorption Properties
Australian 1050m2/gm IAVHigh Adsorption Properties
Australian 1200m2/gm IAVSuper-High Adsorption Properties
Australian Grade Activated Carbon

The difference between 1050 IAV and +1200 IAV is the amount of surface area a gram of carbon has. the +1200 IAV Australian carbon has a more porous microstructure than the 1050 IAV, which allows it to adsorb higher amounts of odors per gram. We will dig deeper into the importance of the surface area of carbon in the next section.

2-Carbon Filter Particle Size

Basically, there are two main types of carbon particles in any carbon filter: they are Granular carbon particles and Pellete carbon particles.

Granular Carbon Particles: As the name suggests, the carbon particles in this type are crushed down to granular sizes, which have a very high surface area per gram of carbon. thus, it has a higher efficiency to adsorb odor.

Pellet Carbon Particles: These carbon particles are much larger in size, and their smaller surface area cannot be compared to granular carbon particles by any means.

To give you an idea of why surface area and particle size matter to a grow tent carbon filter, take a look at the example below.

50 grams of activated carbon that have a sufficient porous surface would match the surface area of 10 football fields. Can you even imagine how large 50 grams of carbon could be and their effect on your grow tent odor control?

3-Types of Plants Grown

The types of plants you are growing do significantly impact the grow tent carbon filter longevity. You cannot grow lettuce in one cycle and herbs in another cycle and expect them to have the same effect on your carbon filter.

Highly aromatic plants that produce larger amounts of odors will quickly fill up the porous microstructure of any carbon filter particles.


Grow tents get high humidity levels all the time. It happens as a result of the continuous presence of water and heat in the same place.

The definition of humidity is the quantity representing the amount of water vapor in the atmosphere. This means that the higher the humidity inside the grow tent, the higher the amount of water vapor that will be present in the air.

Water vapor tends to enter and occupy large amounts of pores in the carbon microstructure competing with other compounds like odors. As a result, the grow tent carbon filter efficiency will significantly decrease, and the smell might start to get outside.

Controlling the grow tent’s humidity is crucial to keep a carbon filter efficient. You should set your dehumidifier to a maximum limit of 80%.

5-Carbon Filter Type

This is a popular trick that everybody does. However, I am going to share it with you just in case you didn’t know about it.

Carbon filters come in two forms: Reversible and Irreversible.

The reversible carbon filter has two operating ends that you can use. After a while of using it, you can simply reverse the ends and use the other side of the filter to get a longer lifespan.

You are probably asking how exactly flipping carbon filter ends would extend its lifespan. when the carbon filter is in operation, the end that is directed towards the inside of the grow tent gets exposed to higher levels of compounds in the air when compared to the other end of the filter that is present outside. Chemical compounds might be water vapor odors and other stuff.

By reversing the carbon filter ends, you are simply taking advantage of the other side being less exposed to other elements and thus, still have several months of lifespan left available.

If you are more interested in grow tent carbon filters, check this article that I wrote on the cost breakdown for a DIY grow tent carbon filter project.

6-Where You Position The Carbon Filter

Some Growers tend to favor playing their carbon filter outside to save up some space. We need to understand that the carbon filter structure is designed to be placed inside the grow tent by the manufacturer.

Blowing air into the carbon filter instead of sucking air through it is one of many reasons why carbon filters could fail in a shorter time span than normal. Check this post if you want to get more details on how to place your carbon filter outside effectively to save up more space.

How To Know That A Grow Tent Carbon Filter Needs Replacement?

First, you must check if the air is flowing through the carbon filter seamlessly. This means that the exhaust airflow is flowing at its normal rate with no clogging. A clogged grow tent carbon filter is an issue that occurs among a wide base of growers. I wrote an article about the reasons for a carbon filter gets clogged and hot to fix, you can check it out here.

This might seem like an overwhelming question that every grower tends to overthink. However, the answer to it is quite simple. The answer is as simple as “use your nose”. You read it right, using your nose is the most accurate test you could run to know the right time to change your carbon filter in the grow tent.

Step 1: Take A One Day Break Away From Your Grow Tent

Step 2: Before Smelling The Grow Tent, Do Any Excercise To Boost Your Blood Flow

Step 3: Smell The Grow Tent Carefully For Any Smell Leakage

If you went straight to your grow tent and run what I am calling a “Nose Test” on it. In most cases, you wouldn’t smell anything unless you follow the next guidelines.

Being around your grow tent daily will most probably result in you having sensory adaptation.

Adaptation To Grow Tent Smell

Sensory adaptation means simply that your nose gets adapted to certain smells if it has been around it long enough. Some studies have shown that all it takes is two breaths for a nose to adapt to a certain scent, after that, it switches off making you no longer able to smell it again.

Did you ever wonder why your house smells so much different when you return from a 1 week’s vacation outside of town? Sensory adaptation is the answer.

You need to take a long day outside of your home in order to give your sensory nerves a break before returning back and smelling anything.

To enhance your smelling abilities for a temporary short period of time try increasing your overall blood flow. This small trick that is used by perfumers in the fragrances industry before testing out new scents.

Increasing your overall blood flow by doing any type of simple cardio exercise will increase the blood flowing to the olfactory nerves, giving you a temporary boost in your smelling abilities.

How To Clean A Carbon Filter Grow tent?

Following a regular cleaning schedule is critical in keeping the carbon filter efficient. A grow tent is the perfect place for the accumulation of dust and other particles. You should clean your carbon filter regularly every 3 months.

Step 1: get the carbon filter outside the grow tent carefully to avoid any dust falling on your plants.

Step 2: Use a toothbrush to clean the filter’s outer surface of any accumulated particles.

Step 3: Run an air blower into the carbon particles to remove the trapped dust inside.

Step 4: Run a smell test following the guideline mentioned in the previous section.

Step 5: If the grow tent is still smelly, you must reactivate the activated carbon again.

In case that regular cleaning didn’t boost the carbon filter efficiency the way you were expecting. Then it’s time to try reactivating your carbon filter.

How To Make A Carbon Filter Last Longer?

As time passes, carbon efficiency degrades, Reactivating a carbon filter will instantly boost its efficiency. As a result, the carbon filter will last longer periods of time.

It’s funny that I found no one talking about this old-school trick and how significant its effect can be on any carbon filter. You can follow on to the next steps if you want to extend some extra months, or even years out of your grow tent carbon filter.

However, if you don’t have the time to implement these steps, you can go ahead and purchase a new carbon filter instead.

Step 1: Rinse Carbon Particles With Water

Unpack the carbon particles from the filter and put them inside a bowl. Rinse the carbon particles with water till there is no yellow or white color present.

Step 2: Let The Carbon Particles Dry

Place the carbon particles on a metal tray. Place the metal tray in a sunny area till they completely dry out.

Step 3: Heat The Carbon Particles

You should heat the carbon particles for 10 minutes at a minimum of 930°F. In this step, you can use a home oven or a bbq grill. However, make sure to keep direct fire away from the carbon particles to avoid them turning into ashes.

Step 4: Let Carbon Particles Cool, Then Topp them Up

Carbon will take a while before it finally cools down so make sure to leave sufficient time for it. After the heating process carbon will lose around 10% of its total final mass, you should topp it up with new activated charcoal to make up for the mass loss.


All of the mentioned information in this article will have a bearing on how long your carbon filters will last. However, choosing the right type of carbon and being careful to maintain your grow tent humidity level is also important.

Your carbon filter should be able to remove any produced odors from the grow tent, and it should also endure for an average of 1-2 years. You can run a smell test on the grow tent to know if the carbon filter is blocking odors efficiently or not.

If you would like to try and boost the grow tent carbon filter instantly, you should reactivate the charcoal again using the guidelines I have mentioned above

Frequently Asked Questions

How Long To Keep A Carbon Filter Running In A Grow Tent? In General, carbon filters must operate for 24 hours, 7 days a week to eliminate odors from leaking out of the grow tent.


Activated Carbon

Sensory Adaptation

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