Last Updated on December, 2023 by Rob Wilson
Best Carbon Filter for Grow Room 2020: Most growers would claim that it is not growing weed which is hard, it is keeping it a secret which is hard! One of the biggest ‘tells’ that you are growing weed is the strong smell that comes out of the plants. Marijuana has a very strong and a very distinct smell which can be easily identified even by non-smokers and can put you in an awkward position if people begin to suspect you about the smell. In order to eliminate smells while you grow your weed, you need carbon filters. Over the course of this article, we shall take a closer look at some of the best carbon filters for grow rooms.
We will first take a look at what carbon filters are and why are they important. This will be followed by an analysis of the 7 best carbon filters that you can buy off Amazon right now! We shall then observe the factors that you must consider before you buy a carbon filter. Post that we look at setting up and cleaning a carbon filter. We then take a closer look at some alternative ways to remove the smell if you don’t want to use a filter. Finally, we conclude after answering some weed-related Frequently Asked Questions (FAQs).
Let us now begin by answering the most basic question at hand: what is a carbon filter and why is it so important for those who grow marijuana.
What is a Carbon Filter? Why is it Important?
A carbon filter is an extremely important part of an air purification or filtration system. Carbon has a number of properties as a chemical but as a substance one of its most important properties is that it has a very absorbent nature and it is this property of carbon that is used in activated carbon filters which help in trapping odours and particulate matters.
These filters are of a particular use to people who want their surroundings to be free of odors. This is of particular importance for someone who wishes to grow marijuana because of the strong and pungent smell that the plant leaves behind. Marijuana’s smell is not only strong but also very distinct and is an immediate giveaway for anyone who has been trying to hide the fact that they are growing weed. Moreover, it is not just the smell of cannabis plants, but also the smell that comes from fertilizers, nutrients, pesticides and other similar products that you might be using to enhance the plant.
Another great benefit of using a carbon filter is that it can ensure that the dust particles and other dangerous compounds that can cause diseases in plants are also eliminated thereby ensuring that your plants remain safe and healthy.
Best Carbon Filter for Grow Room in 2020
#1. iPower 4 Inch Air Carbon Filter
This carbon filter from iPower comes in as a small but powerful offering for growers looking forward to eliminate the smell of marijuana from their grow room. This is a multipurpose filter which can act as both an intake filter as well as an exhaust filter. What really stands out about this filter is the fact that it is made up of 1050+ IAV Australian RC412 Activated Carbon, which is one of the most absorbent kinds of carbon available for the growers that ensures that it can easily capture the odours.
The filter comes with an airflow of 200CFM, and measures 4” with a flange ducting of 12” length. The flange as well as the base are reversible which ensure that the life of the carbon filter can be increased to the maximum possible efficiency. This carbon filter is great for growers who are looking forward to growing marijuana in their grow rooms because it can not only capture all sorts of smells but also certain harmful chemicals that are present in the environment and ensure that both you and the plants are getting a good air.
There are four layers in this filter – the pre-filter, the outer mesh, the charcoal layer and the inner mesh. The inner and outer mesh have small holes in them (53% area is open) which helps make sure that the air flow is proper. The filter cap is made up of durable aluminum and the overall life of the filter can be up to 1.5 years. The pre-filter needs to be changed every six months for optimal performance. The price of this carbon filter is also quite affordable and it does not burn a hole in your pocket. Priced just under $40, this is an ideal option for those who are not growing their weed in a really large setup but would like to ensure that the smell remains contained.
- Eliminates bad odours as well as some harmful elements from air
- Very durable, can last for 1.5 years
- Can work for intakes as well as for exhaust
- Some users have had a hard time claiming warranty on the product
#2. VIVOSUN 8 Inch Air Carbon Filter Odor Control
When you compare this carbon filter with the one above, this is twice as big as the one from iPower. The VIVOSUN carbon filter measures 8 inches and is a highly trusted name in the markets. VIVOSUN is the leading player when it comes to weed-related products and they make practically everything from grow tents to grow lights to many other products that a grower would require to grow marijuana. This is one of the best carbon filters for grow rooms because it comes with a 1050+ Australian Virgin charcoal that ensures that all the bad odour is easily trapped in it.
Similar to the iPower filter, this carbon filter from VIVOSUN is also made up of the same four layers featuring a pre-filter, and a carbon filter which is layered between the inner mesh and the outer mesh. The inner and outer mesh in this filter too, come with numerous holes in them so that they provide a large open area for smoother air flow. The flanges are detachable and reversible in this carbon filter too to increase the life of the filter. This carbon filter measures 8 inches in width and 22 inches in length. A carbon filter belt comes with the package.
This filter, too, works both ways acting as an intake filter as well as an exhaust filter. The filter weighs about 20 pounds and is a great option for those looking forward to buying the best carbon filters for grow tents. The filter can last you for a little over a year when you use it in an optimal manner. Most growers have pointed out that it can last between two to three harvests. It comes with one pre-filter and you would need to replace it after about four to six months of use. Overall a pretty decent option for growers. Also available in 4-inch and 6-inch variants for those who have smaller requirements
- One of the most trusted names in the industry when it comes to equipment for growing marijuana
- Durable, made of good aluminum
- Lasts for 2 to 3 seasons
- Good for those looking for slightly larger-sized filters
- Some users have complained of reduced air-flow after a few months of use
#3. CoolGrows 6 inch Air Carbon Filter
The first filter on our list was of 4 inches, the second filter was twice that size – 8 inches. However, this carbon filter from CoolGrows measures 6-inches and finds a sweet spot between the two, making it a good option for medium-scale growers as well as large-scale growers who are looking forward to remove the odour from their grow tents. Made out of galvanized steel, this is indeed a decent option for those looking forward to buying a durable filter compared to those made out of aluminum. There’s also a four-inch variant of the same carbon filter available for those who might be looking forward to using a smaller sized option.
This is a highly absorbent carbon filter which contains 1050+ IAV Australian virgin charcoal bed – a common practice for almost all good carbon filters these days. While this filter is 6 inches in breadth, it is 18” in height, 2” bigger than most other similar sized carbon filters which measure 16”. Moreover, to ensure that this lasts longer, you can remove the flange and the base and reverse the charcoal canister. The carbon area filters 99.8% of the air that flows through it and has a very high filtration rate. Moreover, the 53% open area in the mesh also allows a large volume of air to flow through.
This carbon filter from CoolGrow functions not only as an intake filter but also as an exhaust filter. Another good thing about the prefilters that are included in this carbon filter are that they are washable and you won’t really need to replace them with the frequency that you might have to do with some other similar filters. While the company has not given any exact estimates on how long can this carbon filter last you, the consumers who have used this have reported it to last a little over a year. A good choice for those looking for the best carbon filters for grow rooms.
- Purifies over 99% of the air that flows through it
- Uses 1050+ AV Charcoal bed
- Absorbs all smells from grow room very well
- The CFM levels are slightly lower compared to some other carbon filters
#4. Amagabeli 4 inch Carbon Filter
Made out of galvanized steel, this carbon filter from Amagabeli is a good choice for growers who have a smaller setup and are looking forward to buying a 4-inch carbon filter. This is a great carbon filter which can function for intake of odours and it can also be used as an exhaust which can pump out all the bad air from the grow room – a good choice for both your needs! The core filter is 4 inches wide but if you look at the entire body, it is 6” in width and 13.4 inches in length. Featuring the Australia Virgin Coconut activated charcoal bed, this is among the best carbon filters for grow rooms.
This Amagabeli 4-inch carbon filter is made up of four layers: a filter core (pre-filter layer), followed by the outer layer of the core (basically the outer mesh), followed by the activated carbon bed and then finally the inner layer which is the inner mesh. While most typical carbon filters offer you with a 53% open area for air flow, this carbon filter offers you a 55% air flow area which is a good plus point. The steel body ensures that the filter is durable and does not corrode in a humid environment. The pre-filter is a changeable layer that needs to be replaced every six months.
The company claims that the filter can purify over 99% of the air that passes through it. This is a relatively lightweight carbon filter as it weighs only 8.55 pounds. The recommended CFM for this carbon filter is 250CFM at the most. This is a great option for those who want to buy a carbon filter for a small grow tent of about 4×4 size.
- Very durable
- Can last for a long time
- Pre-filters are washable
- Eliminates odors really well
- Slow customer service
- Some users have found the air flow to be a little slower than usual
#5. TerraBloom Air Carbon Filter, 6″ x 24″
Somewhat of a larger filter for those who have needs that won’t be fulfilled by a 4-inch carbon filter, this comes from TerraBloom and has quite a distinct look to it. Most carbon filters that you see would usually be the typical greyish coloured steel products. However, this one is a black coloured variant and it makes use of a premium-quality charcoal – the RC-48 Charcoal Carbon which comes from Western Australia. The carbon bed is 46mm thick and it features 15% more carbon compared to typical carbon filters of this size which come with a 38mm bed.
While the duct opening is that of 6 inches, the exact dimensions of this carbon filter are 9.6” x 24.6”. Each set that you purchase comes with two pre-filters (as opposed to only one in most other filters). This ensures that you have to spend less money on replacing your carbon filter. This is a great carbon filter for those looking forward to using a carbon filter for high-speed inline fans as it can filter airs coming in at a speed of as much as 550CFM.
Compared to many other carbon filters which have a life of upto 1 to 1.5 years, this carbon filter can last the growers for much longer as the company claims it can last you 24 months. In addition to this, the company is also aware that some growers might not people to know what they are ordering off Amazon. For this, they ship their products in a plain brown box package without any labels or identifiers on it so that no one can know what you have ordered. For anyone who is looking for a great carbon filter which can eliminate the smells and can last for a long time, this is indeed among the best carbon filters for grow rooms and something that people must consider.
- Thick layer of carbon
- Can handle airflow up to 550 CFM
- Removes all odors from the air really well
- Lasts for upto 24 months
- Comes with two pre-filters
- Some users have had delivery issues as the packaging wasn’t so good
#6. GROWNEER 4 Inch Air Carbon Filter with Reversible Flange Odor Control
This is a four-inch carbon filter which comes with reversible flange which ensures that the filter can last for a longer time. The filter is manufactured by growneer and is among the best carbon filters for grow tents for those growers who have smaller-sized setups. The filter also doesn’t cause a stress on your pockets as it costs under $35. This is one of the cheapest carbon filters that you can get on Amazon but performs really well. The filter ensures that the odors are all filtered really well and are eliminated from the surroundings.
This carbon filter makes use of a charcoal bed using the 1050+ IAV Australia charcoal. While the duct for the carbon filter is 4” the actual size of the product is 7.5” x 12”. Design-wise too, it has been crafted with excellence as it features a cone-based shape on the inside that makes sure that the effectiveness of the active carbon improves. The flange and the base can be removed and reversed by allowing the filter body to flip upside down which makes sure that the smell filtration goes on for a longer time.
The package comes with one pre-filter as well as one filter belt to hang the filter. The pre-filter needs to be changed every six months to ensure the filtration process happens smoothly and that the air flow is clean. The filter weighs 5.78 pounds and removes the odours of marijuana really well.
- Cost effective
- Comes with a pre filter
- Removes odor well
- Loss of airflow over time
#7. Phresh Filter 8 in x 39 in 950 CFM
Last but not the least, Phresh is a good brand when it comes to getting carbon filters. The company has a number of options available for growers of all sizes but this is a good option for those looking for a large carbon filter. An 8 inch carbon filter is a heavy-duty option for heavy-duty growers. Growers who have a large grow tent would need something like this in order to eliminate the smells that come from their tent. Given that weed has a very strong and a very distinct smell, large-scale growers need something like this in order to ensure that the smells remain contained. This is one of the best carbon filters for grow rooms for large-scale growers.
Coming in with a large 8inch duct hole, the main carbon filter layer of this filter features a 46mm (18″) RC-48 activated, certified virgin carbon bed. This comes with a pre-included and prefitted flange and base which makes it easier for first-time users. The flange is riveted and cannot be removed or reversed. This comes with a very unique ‘anti air bypass system’ which makes sure that the air is filtered really well and no odour is left behind.
The inner and outer layers of mesh between which the carbon bed is kept are 51% open which ensure a decent airflow. The exact dimensions of this carbon filter are 11.5 x 12 x 42.5 inches and it weighs 37.5 pounds. While the price of this carbon filter is a little high for some users, the fact that it is a great option for big-sized grow tents and grow rooms make it an ideal candidate. However, we strong recommend users to check out more details about this product before they buy it as only limited details have been provided by the seller on Amazon.
- One of the best carbon filters for grow tents that are large (8×8 and above)
- 18” carbon bed of good-quality charcoal
- Durable and strong
- Only limited details available
- Flange is riveted and cannot be reversed
#8. G-HYDRO 6 Inch Air Carbon Filter Upgraded
G-Hydro is an upgraded carbon air filter then its peers. It offers a lot more than its counterparts, and the secret lies in the almost perfect design, which is improved. The filter provides higher efficiency with increased pollutant absorption with a special design. The 6-inches extended carbon filter is fitted with 150 GSM high-quality prefilters, and the best 1200+RC48 activated carbon from Australia. The activated carbon is not any standard carbon but includes a specially designed carbon particle for improved efficiency. It is most absorbent in the market and offers up to 100% filtered air.
The build of the filter involves stunning matte panel ventilation with a layer of the prefilter and the super absorbent activated carbon. The panel is tightly knitted in a hexagonal design, offering more exceptional ventilation, and the prefilter takes care of most of the pollutants. The make of the filter involves ultra-light but sturdy ABS material along with flange and base, which have long hole design. The flange and base are reversible for longer life of the filter.
The filter offers superior performance with improved ventilation of more than 65%, which is typically around 50% with the hexagonal panel. The odor management is increased with best in class carbon along with the prefilter and last but not least, the build quality, which takes longevity to another level. So, this product is definitely a great choice with modern and needed improvements and increased performance.
The dimension of the G-Hydro upgraded carbon filter is 17 x 9.5 x 9.2 inches and weighs a little over nine pounds. Also, the product comes with two replacements for prefilters and a pair of carbon filter belts.
- High-quality activated carbon from Australia
- Hexagonal panel for increased ventilation
- Long-lasting reversible flange and base
- Modern, matte look
Buyer’s Guide: How to Choose the Best Carbon Filter for Grow Room?
Now that you know what a carbon filter is and what its benefits are, as well as which are some of the best carbon filters for grow rooms in 2020, let us now look at the buyer’s guide. Here, we discuss the factors that you need to keep in mind before you buy your carbon filter.
- Size: The size of the carbon filter as well as the size of the grow room need to be considered before you purchase the filter. If you are growing in a small-scale setup, you would perhaps be alright with using a small-sized carbon filter as it will easily be able to absorb all the smell from your setup. However, if you are growing in a large tent, say, 8×8 or above, a 4-inch carbon filter won’t be enough for your needs and you would require larger carbon filters to eliminate the odor that comes out of it. Similarly, getting a large filter for a small room is also pointless because that would be a waste of your money! Hence, you need to know exactly what size of the filter should you be looking for.
- Airflow: Check if the amount of air that can flow through the carbon filter of your choosing is sufficient for your needs. Sometimes the inline fans that you have might have a high CFM rate but the carbon filter might not be able to process it. Your inline fan, ducts and carbon filter all need to be in a proper accordance in order for the airflow to be good. Usually, we recommend buyers to get all three elements from the same company so that the levels remain equal and you do not face airflow problems.
- Material: By material we mean the exterior of the carbon filter, as well as the interiors. The exterior of most carbon filters is made of aluminum or steel which are the two standard metals used for building them to ensure durability. Some growers prefer steel over aluminum but we have found both to be almost the same in terms of durability performance. In addition to the exterior, the interior is what matters the most. The kind of material that is used inside decides the effectiveness of the filter – always check how much carbon your filter provides and what kind of carbon it provides. The best kind of carbon is usually Australian Virgin charcoal so look for these things before you buy the carbon filter of your choice.
- Multifunctionality Support: Most carbon filters work two ways – they can pull the bad air in them and then they can also pump out the bad air. Check if the carbon filter that you are buying has the support for both the functions. In addition to that, most carbon filters can also purify the air of certain particulate matter such as pet hair, pollen, and dust. Check if the one you are planning on buying can do all that.
- Warranty: Warranty is something that every buyer, regardless of the product, should keep in mind. Be especially careful of this if you are buying a carbon filter which is north of $100. While you can find many small-sized filters at around $40-$50 (and some even cheaper), as the size and the utility increases, so does the price. Hence, you need to check the warranty and return policies once before you buy the filter of your choice.
- Price: Last but not the least, a carbon filter comes at a price. Always set a budget before you head to buy one and make sure you follow that. The more money you are willing to shell out, there’s always something better available. However, do you really need it? Make sure you set a budget and follow it to the T else growing marijuana indoors can turn out to be a costly affair!
How to Set Up a Carbon Filter?
A carbon filter will not function in isolation. It is a part of a larger setup where you are putting together a number of things such as the inline duct fans and the pipes. Basically, if you keep the carbon filter inside the grow tent, you are using it as an intake mechanism where it pulls in all the odor and the air from the grow tent and via the ducts it throws it outside where it provides purified air without the odour. However, if you are planning on using the carbon filter for exhaust mechanism, it will push the air out of the grow tent.
A carbon filter is usually hung to the entire setup with the help of the carbon filter straps that you are getting. Most growers tend to use these straps and belts and tie the filter to the upper rod of the grow tent. Growers must also make sure that the seal between the carbon filter and the fan is air-tight otherwise it might not work properly. One last thing that you need to take care of while installing a carbon filter is ensuring that it hangs at just the right distance. Keeping it too close or too far from the plants might not result in proper filtration of the air. These are the things that you need to keep in mind when you are setting up a carbon filter. Let us now take a closer look at what can be done to take proper care of the filter:
How to Take Care of Your Carbon Filter?
Just knowing the best carbon filters for grow rooms and buying them and setting them up is not enough. You also need to know how to make use of these filters properly and how to maintain them well. Here’s how to take care of the carbon filter that you have bought:
- Do not clean your filter in the grow room. Take it out in an open space to clean it.
- Shake it and spray water on it so that larger chunks of dirt can be removed at first
- Followed by that, submerge this carbon filter in a mix of water and soap for about 15 minutes and rinse it in that
- Let it dry in sunlight for a while
- When it is dry, vacuum it so that any excess carbon is taken off it
This is how you clean your carbon filter. One last tip before we head further into our next segment is that you need to make sure that once it has reached full capacity you discard it and get a new filter because using it beyond full capacity might actually be counterproductive for you.
Alternative Ways to Get Rid of Marijuana Smell
While making use of a carbon filter is the best way to get rid of the smell that marijuana leaves behind, there are also some alternative ways via which you can achieve the same results.
One of the best ways to get rid of the smell of weed is by having it masked by another smell which overpowers it. This can be achieved by using something like incense sticks or scented candles, or even by spraying large volumes of air fresheners around it. If the smell is very strong, the last resort you have is cooking some popcorn and allowing it to burn. The smell of burnt popcorn is one of the strongest and the most overpowering smells that can easily mask the smell of weed for a long time. While this is a good short-term solution, this won’t be forever and as these smells wear off, the smell of weed will begin to dominate the air once again and you will again need to repeat one of these methods.
Another solution to getting rid of the smell of weed from your grow room without using a carbon filter is opening up a window and putting a pedestal fan facing the open window and turning it on. This makes it act like an exhaust fan which makes sure that all the smell from inside the room goes outside. However, you need to be careful because this would blow out the smell of weed from your room into the street and this might raise an alarm among the neighbours or law enforcement.
Frequently Asked Questions: FAQs About Carbon Filters for Grow Rooms
Here are some of the most commonly asked questions about carbon filters for grow rooms that you might have when it comes to growing marijuana indoors.
1. Why does weed smell so much?
The smell that marijuana leaves behind is very strong and very pungent, and is an instant giveaway for anyone who is smoking weed. This is a very strong smell and one often wonders as to why does weed have such a strong smell. The answer to this question is that this smell originates from compounds that are made in the cannabis plant known as terpenes or terpenoids, which is basically a type of an essential oil produced by the plant and all flowering plants produce that. Terpenes can produce different kinds of smells and they have different effects on each plant.
Some people often believe that the smell of weed comes from tetrahydrocannabinol (THC). However that is not true and THC does not have a smell of its own.
2. Is a carbon filter 100% effective against odours?
It won’t be right to say that a carbon filter gives you a 100% effective solution against odors of all sorts. However, when it comes to the smell that marijuana leaves behind, a carbon filter can filter out most of the smell but there’s still a chance that there still might be some traces of smell that can be left behind, particularly if you have been smoking in the area and the dust has settled down on furniture around you. You would then need to vacuum those surfaces to make it 100% smell free. However, it would be fair to say that it is at least 85-90% effective in eliminating odours.
3. How often do you need to change the filters?
It depends on filter to filter. Most pre-filters need to be changed every six months if they are non-washable. The washable filters can last you for a little longer but over the course of time they too, would need to be changed. Most carbon filters come with one pre-filter pre-installed. Some even come with two so that you can save on the cost of buying a new filter. However, pre-filters do need to be changed or else the effectiveness of the carbon filter will be hampered.
4. How to choose the right size of the filter?
Whether you want to buy a 4 inch carbon filter or a 12 inch carbon filter is purely up to your needs. If you have a large grow room where you have lots and lots of weed plants growing, you would require to buy a larger carbon filter or multiple small filters, depending on how other parts of your setup are. The size of the filter is basically directly proportionate to the amount of plants you are growing and the size of the room.
5. Which is the best carbon filter for me?
There is no objective answer to a particular product being the best carbon filter for grow rooms for your needs. This is a case to case scenario and every person might have a different sort of a need. For growers who have a small grow tent with just a few plants growing in them, a 4-inch carbon filter would do. Others who have a larger setup with more number of plants would require a bigger and more heavy-duty sort of a carbon filter in order to ensure that no smell remains.
6. Do carbon filters work for grow rooms?
Yes, carbon filters work for grow rooms, and if you are growing weed in there, then you need one. These filters discourage the strong smell of your cannabis from escaping the tent and keep your grows discreet. Also, they can be installed to filter the air going into your grow room or cabinet to control the environment with no pollutants and other impurities. They are effective to use in grow rooms and cabinets.
7. What are the best carbon filters for grow rooms?
There are various carbon filters for grow rooms available in the market. You can find the best amongst them in the article above. The best ones will be in the ideal size and capacity of your grow and quality carbon filter fitted ones; otherwise they are almost the same. So, pick carefully.
8. What size carbon filter do I need for my grow room?
Various sizes are ideal for different sizes of grow, and you need one bigger if you have substantial grow. For a small tent and room, a 4-inch carbon filter or multiple are required, and for a larger area, a 6-inch one or multiple should be used, which largely depends on the size of grows and smell.
9. How long do grow room carbon filters last?
The carbon filters of your grow system tend to last a long time due to the controlled environment of your grow setup. They typically last for several months that can stretch up to a few years. But, we advise them to change every 18 to 24 months and in heavy use in 6 to 12 months. The longevity depends on the size of grow and smell of the plants.
10. How often does activated carbon need to be replaced?
The activated carbon needs no frequent replacement in your to grow setup. They tend to last for several months that may last up to several years. But, users must replace them after 18 to 24 months for earlier if they feel inefficiency in the filtration. Cleaning and maintenance will ensure longevity and increased efficiency without the need for a premature replacement.
11. How do you filter the air in a grow room?
The most effective way to filter the air in a grow room or out a grow room is through a carbon filter. Placement of a carbon filter for airflow in your grow room or flowing out, or both will result in filtered air, no pollutants, and also no odor. This filter effectively removes all the unwanted impurities for the better of your plants and even your surroundings. You can also use other filters along, but these are by far the most effective.
We hope that this article has helped you gain a better perspective on understanding carbon filters and the role that they have to play when it comes to cleansing the air off all smell and odour. There are a number of things that need to be considered before you buy the carbon filter and we have tried to provide a fair picture of what all do you need to look for before you buy it. We have also tried to answer some of the most commonly asked questions about carbon filters including those about how to set them up and how to take care of your filters. Do let us know in the comments below or drop us a mail to let us know if there’s anything that we missed or if there’s anything more that you would be interested in knowing!
Happy Growing! 🙂
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