best carbon filter for grow rooms

Best Carbon Filter For Grow Room: Buyers Guide

Are you operating your own marijuana grow room and growing lots of pot? If so, you might be worried about those strong smells that occur during the flowering period. Yeah, flowering pot plants really do put out quite the stink, and if you are looking to be discreet, it’s not good.

However, there are tools out there, such as carbon filters, which help to eliminate those odors, plus they can help control airborne pathogens too.

Today, we want to help you find the best carbon filter for grow rooms and we have narrowed it down to 7 particular options with a variety of sizes and features. Aside from that we want to tell you exactly what you should be looking for to get the most benefit for your grow room.

What Is A Carbon Filter & What Does It Do?

Simply put, a carbon filter is a unit which sucks in air and is designed to filter it. Activated carbon, usually in the form of charcoal, is one of the best odor absorbers out there, plus it also has the ability to absorb a lot of airborne pathogens, such as bacteria, viruses, mold, and other such things too.

They often come in the shape of a cylinder and contain activated carbon. Now, you can purchase carbon filters with the air fans included, and separate fans and carbon filters too. However, you do need a fan to either suck or push air through the filter.

The bottom line is that if you have a grow room and you want to reduce odors, and reduce the risk of disease, a carbon filter is a big time grow room requirement.

Best Carbon Filter For Grow Room: Reviews

Here we have what we think, and what are generally considered to be the best options for grow rooms out there right now. Here we have selected a variety of types and sizes, so you can choose the one which works best for you.

1. iPower 4 Inch Air Carbon Filter


Here we have a great little carbon filter that works fine for small grow rooms and grow tents with just a few plants. Moreover, it features a maximum airflow rating of 200 cfm, or 200 cubic feet per minute, which is more than enough for a small grow room.

It’s probably not the best for a very large grow room with lots of plants, but it works fine for smaller purposes.


This particular option uses 1050+ IAV Australian RC412 Activated Carbon to remove odors and pathogens from the air, which in all reality is one of the best types of carbon around for this kind of thing.

This layer of carbon is 50 mm thick, which is pretty substantial and ideal for controlling the odor created by a few plants.

What is really cool is that the iPower Carbon Filter comes with a pre-filter included, which helps protect the main filtration unit from damage, and keeps it going for longer before the carbon needs to be replaced.

There is also an inner and outer mesh included here, which helps to greatly increase airflow, and this filtering efficiency and efficacy.


Something else which stands out about this particular carbon filter is that it comes with a reversible flange, which means that it can used as both an air intake and an outtake system, depending on how you want to set it up.

The iPower 4 Inch Air Carbon Filter is fairly easy to install, as it features a plug and play design, but do keep in mind that the ducting required for ventilation is not included.


  • Great for small purposes.
  • Reversible flange.
  • Plug and play capability.
  • Dual direction.


  • Not ideal for more than a few plants.
  • Ducting & fan not included.

2. Phresh Carbon Filter


Here we have a slightly larger option to go with, the Phresh Carbon Filter, which is a 6 inch filter. What is nice about this particular option is that the base and top are both made of aluminum, which is lightweight, but still very durable.

The result is that the Phresh Carbon Filter weighs about half as much as leading competitors, although it still weighs close to 20 pounds, so you do need the right equipment to set it up.

In terms of the size, the Phresh Carbon Filter is ideal for small-medium size grow rooms, and more or less for any size of grow tent. This thing can suck up 550 cubic feet of air per minute, which is pretty impressive.


The virgin activated carbon bed, helps to eliminate mostly all weed odors and airborne pathogens that may harm your marijuana crop. It also features a custom mesh on the exterior which helps increase overall airflow by 51% for a high rate of filtration efficiency.

There is also a very unique air anti-bypass system included, which ensures that all air which passes through the carbon is properly filtered.

On a side note, the carbon used here is machine packed, something which also helps increase efficiency.


The Phresh Carbon Filter does come with a high quality flange, although it is not reversible in nature. What we do like here is that this option also comes with a pre-filter, which helps keep this item in good condition for much longer, and also leads to you having to replace the carbon much less often.

All in all, although the ducting and mounting hardware is not included here, it is a great option for removing odors and pathogens in grow rooms.

We do like how this option comes with a very high level of durability, and a pretty decent warranty too.


  • High level of durability.
  • Lightweight design.
  • Ideal for small-medium grow rooms.
  • Great filtration efficiency.


  • No mounting hardware, fan, or ducting included.
  • Some shipping issues have been noted.

3. TerraBloom Acticated Charcoal Carbon Filter


Yeah, here are moving to an even larger option, as the TerraBloom Charcoal Carbon Filter is an 8 inch unit. In terms of pure power, this thing definitely does not come up short. Yes, this unit is designed to handle any size of grow tent and it can handle some pretty big grow rooms too.

This carbon filter has a power rating of 750 cfm, so it can handle up to 750 cubic feet of air per minute, which is pretty impressive, and will come in handy for large spaces.

Now, the TerraBloom Filter does weigh well over 20 pounds, and the mounting hardware and ducting is not included, so you will need to figure out how to mount it properly, especially so the weight is well supported, but it really does not change the fact that this thing does work very well.


This particular unit features a massive 1.8 inch thick layer of activated charcoal which has the power to remove all odors and pathogens from a fairly large grow room.

It’s premium activated carbon and it really does work like a charm. o ensure a high level of durability and a great lifespan, this particular carbon filter comes with 2 separate pre-filters.

In all reality, this filter should last for roughly 2 full years before the filtration media, the carbon, needs to be replaced, which is indeed better than most other options out there right now.


What you do need to know here is that this unit is specifically designed for use with inline fans, so you do have to own a compatible inline fan to use it.

This thing is big, it’s powerful, and long lasting too. It definitely gets the job done, although it might be a bit difficult to install.


  • Quite durable.
  • Media does not need to be changed often.
  • Can handle some pretty large grow rooms.
  • High quality pre-filter.


  • Very heavy.
  • Can be difficult to install properly.

4. Phresh Intake Filter


Yes, here we have another carbon filter from the Phresh brand name, and this one is about twice the size of the other one we looked at from the same brand name. This Phresh Intake Filter is a massive 10 inch filter. Well, it’s not massive per say, but it is intended for larger purposes.

This thing can handle up to 1,000 cubic feet of air per minute, which is more than enough for any grow tent and for very large grow rooms too.

It is said to kill 99.9% of bugs, mold, odor, and pathogens, which is fantastic if you are worried about the wellbeing of your marijuana crop.

What does need to be said about the Phresh Intake Filter is that it’s not the easiest to install due to this, but what is nice is that it only weighs 6 pounds, which is insanely lightweight, and it’s thanks to the special design of it.


Keep in mind that the Phresh Intake Filter used a really thick pad of high quality activated carbon to remove odors and pathogens from your grow room.

Generally speaking, under normal circumstances, this thing should last for about 2 years before the carbon filtration media requires replacement, which is a long time indeed.

Keep in mind that this option can be used for intake filtering, scrubbing and low intensity exhaust filtering, but it really is an inline option, one which does not come with an included inline fan, so you will need to have a corresponding inline fan, and you’ll need the proper ducting too.


Now, although it is very lightweight, it is not the most durable option out there, so you do want to be careful about dropping it and banging it into things.

Something we personally appreciate about the Phresh Intake Filter is that it is made with 90% recycled materials, and it itself is 100% recyclable once it is time to trash it.


  • Big and powerful.
  • Very high quality filtration media.
  • Recyclable and made of recycled materials.
  • Very lightweight.
  • Media does not require replacement often.


  • Limited durability.

5. VIVOSUN 6 Inch Inline Duct Fan with Carbon Filter

Alright, so far we have only looked at simple carbon filters, ones that do not come with an air fan for airflow, or any sort of ducting. However, here we have a cool option that comes with the carbon filter and an inline duct fan too, although it does not come with ducting.

The fact of the matter is that if you just want the fan and the carbon filter for odor control, this is a good option to go with, and even if you want to use it for ventilation purposes, buying the ducting for it is not that hard, and on that same note, installation is not difficult here either.

The Fan

First off, the fan itself here has a top speed of 2,450 RPM, which is pretty impressive no doubt, but it only puts out 50 dB of noise, so it is a fairly quiet option. Now, the fan itself is not the most durable or long lasting, so be careful with it, as it has been known to break down with prolonged use.

What you may like here is that the fan included with this carbon filter has 3 speeds you can choose from.

The Filter

What you also need to know here is that the carbon filter itself is rated for 440 cubic feet per minute, so it works well for small and small-medium size grow rooms and grow tents. No, it doesn’t have a ton of power, but it works fine for smaller grow room applications.

Moreover, this thing is made with high quality virgin activated charcoal, and it does have a substantially thick charcoal bed, so it does a pretty fine job at clearing up odors in smaller grow rooms.

This filter does come with a pre-filter to keep it in working order for longer, and so that the charcoal needs to be replaced less often. The pre-filter requires replacement every 6 months, but the main filter only every 2 years, roughly.

What is also cool about this carbon filter is that it can be used as an intake and outtake, thanks to the reversible flange.

6. iPower 4 Inch Carbon Filter & Inline Duct Fan Combo

Here we have another good inline fan and carbon filter combo, this one being a bit smaller than the previous one we looked at. What we really like about this iPower 4 Inch Carbon Filter & Inline Duct Fan Combo is that it comes with absolutely everything you need to get started.

It comes with a high quality carbon filter, a nice little inline fan, a fan speed controller, some ducting, and mounting hardware too, and it’s all quite cost effective to boot.

If you need something small for a small grow room or grow tent, you need something that’s simple to install, and cost effective too, then this iPower 4 Combo is a good option to consisder. On a side note, you also get a free temperature and humidity monitor included.

The Filter

In terms of the carbon filter itself, this one is rated for 150 cfm or 150 cubic feet of airflow per minute, so it is only ideal for very small grow rooms and grow tents. Speaking of grow tents, this thing is too heavy for grow tent materials, but you could just place it on the ground.

Anyway, the iPower 4 Inch Carbon Filter &  Fan Combo uses a 1050+ IAV Australia Charcoal Filter, which is currently some of the highest quality and most absorbent carbon out there. It also comes with inner and outer mesh to increase airflow by up to 53%.

The included pre-filter is useful because it helps keep the main filter in good condition. The pre-filter should be replaced every half year, and the main filter every couple of years.

The Fan

In terms of the air fan, it’s a nice little 150 cfm inline duct fan. It works just fine and it’s not hard to install either, but it’s also not the most durable or long lasting air fan.

What is nice is that it comes complete with a speed controller, so you can adjust how much filtration is going on in your grow room.

On a side note, the included fan here is quite loud, so it’s not the best if you are looking to operate an incognito grow room.

7. Winix 5300-2 Air Purifier with True HEPA, Carbon Filter

Alright, so this is not exactly a normal carbon filter like you are used to for grow rooms. This is not a carbon filter that requires an inline fan, an outtake system, ducting, or any other kind of accessories for mounting. It does not need to be mounted at all.

In fact, this is more of an air purifier system than anything else. It looks like an average air purifier. It’s a box with vents and fans, and filtration systems, which sit on the ground.

Now, this means that this thing is not ideal if you are looking for ventilation with ducting, but that said, if you just want to reduce odors, pathogens, and more, and you are fine with having recycled air in the grow room, then the Winix 5300-2 is a fantastic option to go with!

Size & Filtration

This thing comes complete with a true HEPA filters that reduces the levels of dust, cigarette smoke, pollen, odors, pet dander, mold spores, and organic chemicals in the air by nearly 100%, so it is a great option for keeping your pot plants free of mold and disease.

On that same note, this option also comes complete with an activated carbon filtration system to reduce odors and kill even more pathogens. Now, this option is not the best for large grow rooms or really strong odors, as it is primarily designed for air purification, but it performs amicably in terms of odor reduction too.

It is rated up to 236 cfm, although we would not use it for a grow room larger than 200 cubic feet.

Other Notable Features

What’s nice is that this filter comes with a smart sensor system which cranks the power up or turns it down as needed.

The big downside here is that this thing is really big and takes up a ton of space in a grow room. On the other hand, this air purification unit is nearly totally silent, which is great if you are looking to run a discrete operation.

Grow Room Carbon Filter: Buyer’s Guide

Before you go out and purchase any carbon filter for your grow room, there are some main purchasing factors that you need to keep in mind.

Let’s do a little grow room carbon filter buyers guide so you know what to look for;

1. Area Covered

The first thing that you need to consider here is how large your grow room is and how large of an area the carbon filter in question is rated for.

Some carbon filters are for as little as 150 cubic feet per minute, while others can handle 1,000 cubic feet of air per minute or more.

So, you do have to do a bit of measuring to figure out how much area the carbon filter needs to cover.

2. Carbon Quality

The next thing you need to pay attention to is the quality of the carbon filter media. Generally speaking, 1050+ IAV Australia Charcoal is the best way to go, as it is currently the best kind of charcoal for grow room air filtration.

However, as long as you manage to find high quality charcoal, you should be fine. There are a few different kinds of charcoal filter medias out there, so this is something you might want to look into.

3. Lifespan Of The Filter Media

The next thing that you want to look for in your carbon filter is how long the media lasts before it requires replacement.

Now, all high quality carbon filters will come with pre-filters, which help to filter out all sorts of contaminants before the air gets to the main filter.

This will help to greatly increase the lifespan of the main media before it requires replacement. High quality options should not require you to replace the media more than every 1.5 or 2 years.

4. Included Accessories

Many carbon filters come with only the carbon filter itself, but if you are looking for a full setup, you do want to look for a combo option that comes complete with the filter, an air fan, ducting, and mounting hardware too.

5. Portability & Weight

Some carbon filters can simply be placed on the ground, which is fine if you want to just filter and recycle the air in the grow room.

However, if you want to create a full blown filtration and ventilation system, you will want to pay attention to the size and weight of the unit in question.

For instance, if you are setting up a grow tent, some options may be too heavy for the grow tent to support.


Do Carbon Filters Work For Grow Rooms?

When it comes to odor control, yes, carbon filters work wonders in grow rooms. The best options around can totally eliminate all marijuana odors for discreet growing, plus the removal of pathogens is quite the bonus too.

Do I Need A Carbon Filter In My Grow Room?

Technically speaking, no, you don’t absolutely need a carbon filter for your grow room, especially if you have a small one with just a couple of plants.

However, there is no denying that the removal of pathogens and airborne diseases is a big deal, something that can help protect your plants.

Moreover, if you are worried about marijuana odors, it’s one of the only things that can really eliminate or reduce them.

How Long Does A Carbon Filter Last In A Grow Room?

How long a carbon filter will last does depend on the specific model you get. Some may only last for a few months before the carbon media requires replacement, while high quality models that come complete with prefilters may last for 2 years or longer.

How Often Should I Change My Carbon Filter In My Grow Room?

Once again, this depends on the quality of the filter media, how much air and odors are being filtered in the grow room, and if the carbon filter comes with a prefilter.

Generally speaking, you should not have to change the filtration media more than every 18 months, at least if you have a high quality option. Remember, the filter itself does not require replacement, just the filtration media.

Does A Carbon Filter Remove Smell?

Yes, this is pretty much the only reason why most people get carbon filters for their marijuana grow rooms, because they reduce or even fully eliminate the smell of weed.

How To Choose The Right Size Carbon Filter For A Grow Room?

This is very easy. Simply measure your grow room to figure out how many cubic feet of space it is, so width x length x height.

Once you have figured out how many cubic feet your grow room is, you can then pick a corresponding carbon filter. For more info on choosing the right size, take a look at the included video below.

How To Set Up A Carbon Filter System In A Grow Room?

Carbon filters can be used as intakes or outtakes for air, but it does depend on the model in question.

For a more coherent and easy to understand explanation, we would recommend taking a look at the videos we have included below.

Can I Use A Carbon Filter In A Grow Tent?

Yes, you can absolutely use a carbon filter in a grow tent, but do keep in mind that most grow tents are too lightweight and flimsy to support most carbon filters, so they will need to laid on the ground instead of hung up, which can present some issues.


As you can see, there are plenty of great carbon filters out there, all of which can work wonders for controlling odors and airborne pathogens in your grow room. Now, all you need to do is figure out what size and power level you need, and then you are good to go.

Remember, if you are only growing a plant or two, this might not be necessary, but no matter what, if you are concerned about odors, you definitely want to get a nice carbon filter, even just a small one.

Image credit: Plantlady223 [CC BY-SA 4.0], via Wikimedia Commons