10 Best Carbon Filter for Grow Tent & Grow Room Review

You’ve most likely hopped onto the indoor weed growing bandwagon and are searching for the best carbon filter for grow tent/ grow room or fan filter ducting combo.

Search no further!

An activated charcoal filter for grow tent has to be thick enough to absorb and banish up to 99% of the sharp pungent smells discharged by your cannabis plants’ leaves and buds.

But then again, not all carbon filters are created equal, and finding the right choice takes a bit of research.

Gladly, we’ve done the dirty job on your behalf by researching and comparing 50+ best carbon filters for grow rooms and hydroponics growing systems. We’ve now zeroed in on the top 10 best carbon filters and 5 best carbon filter, ducting and fan combo that’d best suit your grow tent.

As far as our recommendation goes, we throw our weight behind the iPower 4inch Air Carbon Filter. This model seems to blow the others out of the water.

Even so, we’ve got additional options that you might wish to consider depending on your specific preferences and size of your grow tent.

So buckle up, and let’s walk this breathtaking journey together.

1. iPower 4 Inch Carbon Filter

iPower 4 Inch Carbon Filter

KEY FEATURES

  • Weight 6lbs
  • Air Flow: 200CFM
  • 50mm carbon layer thickness
  • Product Dimensions: 8 x 8 x 13 inches
  • 1050+ IAV Australian RC 412 activated virgin charcoal

This 4 inch iPower Air Filter is the best carbon filter for grow tent on the market today. The professional-grade filter brags the 1050+ IAV virgin Australian charcoal, which is considered one of the most adsorbent charcoals in the world.

These special virgin carbons are derived from the oldest and most pressurized source on Earth. Ideally, it’s this 50mm thick layer of carbon that’s responsible for eliminating the nastiest odors, toxins, and chemicals in the air for enhanced growth of your marijuana.

Boasts of an inner and outer mesh with 53% open area for maximum airflow rate, which means it supports an intake filter or an exhaust fan.

WHAT I LIKED

  • Features a reversible flange for superior lasting effects up to 1.5 years
  • The carbon filter cap is built from a premium quality aluminum for maximum strength and durability
  • 50mm thick carbon layer guarantees a higher adsorption performance and removal of potentially ill-fating chemicals
  • Its aluminum construction weighs 50% less than the competition for easy plug-n-play setup

WHAT I DIDN’T LIKE

  • Not Perfect For Large Grow Room

2. Phresh 6 inch air Carbon Filter

Phresh 6 inch air Carbon Filter

KEY FEATURES

  • Weighs 25.6lbs
  • Air Flow: 400CFM
  • Machine packed carbon
  • Cone-shaped internal base
  • Exclusive “Anti Air Bypass” technology
  • 46mm RC-4/8 certified, activated carbon bed

The best carbon filter for your grow room has to optimize the room’s air circulation and eventually odor elimination. This Phresh Carbon filter features a cone-shaped internal base for better air flow. Further, it uses the anti-air bypass technology to ensure your grow room receives optimum air circulation all the time.

For overhauled odor control, this filter uses a 48mm thick RC-48 activated carbon originating from certified virgin carbon bed in Australia. Being 48mm in thickness, it’ll be able to trap maximum odor in the air.

WHAT I LIKED

  • Uses high quality Australian virgin carbon for optimized odor control
  • 48mm thick activated carbon layer eliminates over 95% of undesirable odors
  • Carbon in the filter is machine packed to minimize movements
  • Con shaped base looks attractive and overhauls your room’s ventilation to improve your cannabis yield

WHAT I DIDN’T LIKE

  • A little on the pricier end, but it’s got premium quality features

3. VIVOSUN 6 inch Carbon Filter

VIVOSUN 6 inch Carbon Filter

KEY FEATURES

  • Weight 6.42lbs
  • Dimensions: 6” x 18”
  • 1050+ Australian virgin charcoal bed
  • 6 x 18 inch reversible filter flange and base
  • Changeable Velcro pre-filter and carbon filter belts

The VIVOSUN 6 in Carbon Filter is our runners up model, for various reasons. Like our recommended choice above, this one contains superior quality 1050+ RC48 virgin Australian activated carbon.

Not only does it deliver 100% uninterrupted airflow, but it also captures three times more air impurities, pungent smells and particles than any average filter. Each carbon molecule has an optimized surface area and is magnetically charged to attract all sorts of odors and chemical irritants and expel them from your grow room.

It Has a four-layered construction with inner and outer mesh that offer a 53% open area for incredible air flow. Versatile enough to be used as intake or exhaust filter in multiple setups, such as grow tents, cupboards and cabinets

WHAT I LIKED

  • Flange and base are switchable for optimized service life
  • Offers 100% of filtered breeze stream for unbeatable airflow performance
  • Budget-friendly price with 1-year warranty

WHAT I DIDN’T LIKE

  • A one-year warranty from a big brand like VIVOSUN is somewhat unreasonable. It could’ve been better.

4. TerraBloom 6″ x 16″ Carbon Filter

TerraBloom 6 in Carbon Filter

KEY FEATURES

  • Weight: 21lbs
  • Size: 6 inches
  • Up to 24 months of effectiveness
  • 46mm (1.8inch) thick RC-4/8 virgin carbon bed
  • Includes 2 machine washable pre-filters (black & white)
  • 6 inches duct opening diameter x24 inches filter length

For avoidance of confusion, the TerraBloom Air Carbon Filter is considered one of the best 6 inch carbon filter for grow tents on the market. However, the 6×24 inch TerraBloom Carbon Filter offers the best value for your money, because it comes packed with dozens of FREE accessories.

Besides, it also prioritizes performance using the top-grade RC-48 charcoal carbon sourced from Western Australia. The filter uses a 46mm thick carbon bed that’s machine packed to get extremely minute granules for increased scope of performance. These small granules enable the carbon filter to be used in multiple ways: eliminating plant-based allergens, removing cigarette smoke, scrubbing foul smell from the kitchen or garage, etc.

WHAT I LIKED

  • Supports a broad array of applications
  • Up to four different sizes to choose from depending on your grow tent size
  • Designed with noise-cancelling technology to minimize the noise produced by your fan
  • 8inch (46mm) thick RC-4/8 virgin carbon layer is effective up to 2 years
  • Comes standard with several FREE accessories, including 2x machine washable pre-filters and factory pre-installed flange and aluminum bottom

WHAT I DIDN’T LIKE

  • Comes with 2 filter covers but without hanging straps. You might want to get the adjustable heavy-duty rope ratchet carbon filter hanger separately.

5. AC Infinity Carbon Filter for Hydroponics

AC Infinity Carbon Filter for Hydroponics

KEY FEATURES

  • Weight 9lbs
  • 410 CFM air flow capacity
  • 60mm carbon thickness
  • Heavy-duty aluminum mesh
  • 6 inches duct opening, 16 inches filter length
  • 1200+ IAV premium Australian virgin charcoal

This AC Infinity Air Carbon Filter is among the thickest, most durable and effective charcoal filters for grow rooms on the market today. Its durability is informed by the fact that it features heavy-duty stainless steel flanges, dual-sided aluminum mesh and clothed pre-filter.

Apart from its heavy-duty construction, the flanges fit snugly over your ducting, and are reversible to prolong the life of your filter. This carbon filter is equipped with 60mm thick RC412 premium-grade Australian virgin charcoal rated at 1200+ IAV. The thickened charcoal bed increases the mesh open area to 55% for augmented adsorption rate and unrestricted airflow.

WHAT I LIKED

  • Impeccable build quality with the thickest carbon bed for unmatched durability and adsorption
  • Premium-grade RC412 1200+ IAV Australian charcoal is highly adsorbable and prevents gaseous compounds and foul odors from spreading
  • Aluminum mesh lining the outer body and inner chamber helps maximize airflow and minimize CFM loss
  • An easy-to-wash pre-filter sleeve prevents the buildup of carbon residue and keeps the air filter clean

WHAT I DIDN’T LIKE

  • AC Infinity is currently not selling replacement pre-filters.

6. Coolgrows 4-inch Cheap Carbon Filter

Coolgrows 4-inch Cheap Carbon Filter

KEY FEATURES

  • Weight: 6lbs
  • Size 4 inches (240 CFM)
  • 7 x 12x 10 inches dimensions
  • Reversible flange and base
  • 8% filtered airflow efficiency
  • Pre-filter available as standard

The CoolGrows 4 in Filter is the best carbon filter for grow tent that goes for less than $50. Despite its indomitable affordability, it’s earned 4.3 starts from verified Amazon buyers. What makes this product stand out from the crowd is its durable construction.

This cheap carbon filter is manufactured with premium galvanized steel, which is longer-lasting compared to aluminum. Furthermore, it has a reversible flange and base design, whereby you can reverse the charcoal canister or flip the filter body upside down for reversible smell filtration and extended service life.

WHAT I LIKED

  • Uses 1050+ IAV Australian charcoal for filtering air up to 99.8% to ensure maximum efficiency
  • Comes with a pre-filter for soaking up and eliminating ill-smelling aromas from kitchen, bathroom, drying rooms, etc
  • Its sturdy zinc anodized steel body is corrosion resistant and will last you several years
  • Its inner and outer mesh has about 53% open area to help pass more air quickly and improve the flow rate
  • Ridiculously cheap with a 1-year warranty

WHAT I DIDN’T LIKE

  • Pre-filter has a shorter lifespan. We recommend getting this universal pre-filter replacement if something goes askew.

7. TopoGrow 6″ High CFM Carbon Air Filter

TopoGrow 6″ High CFM Carbon Air Filter

KEY FEATURES

  • Weight: 97lbs
  • Airflow: 450 CFM
  • 6inch flange (10”Hx9”D)
  • Iodine adsorption rating 950
  • Carbon Layer Thickness: 1.5″
  • Zinc-anodized steel housing mesh

If you’d like to enjoy both worlds of reliability and environmentally-friendliness in a carbon filter, then consider the TopoGrow 6 inch Carbon Filter. Ideal for your grow tents and hydroponic growing systems, the filter has a quality design and features a zinc anodized steel casing to uphold reliability. The casing cannot be corroded with chemicals.

Furthermore, it has a 1.5-inch thick carbon layer made from environmentally-friendly coal based activated charcoal. The TopoGrow is sure to meet your exhaust or intake air cleansing needs, with a 450 CFM maximum scrubbing action. Its 950 iodine adsorption rate is highly efficient.

WHAT I LIKED

  • Reliable design with highly adsorbent carbon charcoal
  • Boasts a 20-65 degree Celsius operating environment temperature and 400 degrees Celsius maximum endurable temperature
  • Reversible filter base and flange extends the filter’s life
  • Changeable Velcro pre-filter for removing impurities. Two elastic ropes included a FREE gift

WHAT I DIDN’T LIKE

  • Pre-filter is susceptible to faulting

8. G HYDRO Charcoal Filter for Grow Rooms

G HYDRO Charcoal Filter for Grow Rooms

KEY FEATURES

  • Weight: 73lbs
  • 6x18inches dimension
  • 53% panel ventilation rate
  • 99% particles blocking (dust & odor)
  • Versatility for use in multiple settings

This 6 inch G HYDRO grow room carbon filter is all about versatility, in terms of the ability to be used in various settings and applications. You can use it as an air intake or exhaust filter for diverse applications, including indoor planting tents, basements, kitchens, and bathrooms.

The filter is furnished with premium activated charcoal derived from virgin Australian charcoal – one of the most adsorbent carbons in the world. Each carbon particle has an optimized shape that guarantees 100% filtered airflow.  Moreover, this carbon filter flaunts a 53% panel ventilation rate for increased work efficiency and reduced air volume loss.

WHAT I LIKED

  • It’s versatile and supports odor elimination in multiple settings including cannabis grow tents
  • 1050+ RC-48 virgin Australian carbon offers great adsorbent performance
  • Comes with FREE top-grade replaceable material pre-filter for blocking 99% of particles
  • Has a tapered base design that elevates the adsorption effect of activated carbon

WHAT I DIDN’T LIKE

  • Installation can be headache for those who’re new to this baby.

9. iPower 12 Inch Carbon Filter

iPower 12 Inch Carbon Filter

KEY FEATURES

  • Weight: 24lbs
  • 12 inches flange ducting x 24inches length
  • 50mm carbon layer thickness
  • 53% open area inner & outer mesh
  • Reversible flange & base for extended service life
  • 1050+ IAV Australian RC412 activated carbon for inline fan

This iPower 12 inch Carbon filter is a professional-grade carbon filter for grow room that’s engineered with the most adsorbent 1050+ IAV RC412 Australian virgin charcoal. The inside layer of carbon is 50mm thick, making it one of the thickest carbon filters for decontaminating air in a grow room. Actually, it’s thick enough to address even the nastiest odors in your grow room.

As for durability, this professional-grade filter is built from the highest quality aluminum material. The durable aluminum guarantees superior strength and maximum lasting effects. It’ll help you eliminate bad odor and chemical toxins from your grow room for over 1.5 years.

WHAT I LIKED

  • Inner and outer mesh have a 53% open area for increased airflow
  • Uses special virgin carbons obtained from the most pressurized sources on Earth for optimum adsorption
  • Aluminum construction weighs 50% less than the rivals for simple plug-and-play installation
  • Another best carbon filter fan combo version is available and eliminates excessive heat besides filtering carbon

WHAT I DIDN’T LIKE

  • Sometimes the product is shipped smashed and intake flange bent in half. Watch out.

10. Amagabeli 4″ Carbon Filter for Weed

Amagabeli 4 Carbon Filter for Weed

KEY FEATURES

  • Weight: 48lbs
  • Galvanized steel material
  • Reversible smell filtration
  • Easy mount pre-filter with Velcro seam
  • Activated charcoal & additional filter strainer to prevent carbon leakage

The Amagabeli 4-inch Carbon Filter comes last in our best carbon filter for grow rooms and hydroponics indoor growing system. But never make a mistake and underestimate this filter, because it boasts a staggering 4.4 stars after 170+ real customer reviews on Amazon.

The filter uses a 1050+ IAV Australian virgin coconut charcoal, which is machine-packed to filter 99.8% of impurities in the air. What sets it unique from the rest is its reversible smell filtration, whereby you can use it as an intake filter and exhaust filter. You can use it inside your grow tent to remove pungent smells or outside the grow tent to supply fresh air to your plants.

WHAT I LIKED

  • Provides a 55% open area for increased airflow rate
  • The air scrubber uses galvanized steel material to sustain its durability
  • Its carbon is packed by a machine to provide up to 99.8% filtered breeze stream
  • Has received a high rating and endorsement from REAL buyers

WHAT I DIDN’T LIKE

  • No warranty

5 Best Carbon Filter Fan Combo for Grow Tent

Removing any unwanted gaseous particulates to keep your garden smelling fresh and clean is one of the main maintenances required for a healthy indoor garden. In such cases, an efficient carbon filter fan combo can surely be your best option.

Stinky odor and harmful gaseous particulates can be a very common problem from any gardener if you are growing your plants in an enclosed system as a grow tent. That is carbon filters and ventilation fans are a must when you are faced with such a situation.

Well, it is even better when both these devices come in one whole package! That is why we have reviewed the best carbon filter fan combo for your convenience so you will have a hassle-free experience choosing one combo that will best serve your needs.

So, let us have a quick look on the main features of these devices, along with their pros and cons.

1. VIVOSUN 4″ Fan Filter Ducting Combo

VIVOSUN 4" Fan Filter Ducting Combo

KEY FEATURES

  • 203 CFM Inline Fan
  • 4 Inch Filter and Ducting
  • Included Speed Controller
  • STURDY DUCTING+ 2 Stainless Clamps
  • Very powerful inline fan with low noise level

VIVOSUN Fan filter ducting combo is a three-part system filtration mechanism that has got all your grow tent requirements covered. It has superior carbon quality for thorough odor absorption, leaving your grow tent smelling clean and fresh throughout the year!

So, how did we conclude that this might be one of the best inline fan and carbon filter combo?

Well, for starters it comes with ducting and clamps which are highly durable and long-lasting due to their corrosion-resistant and temperature proof features.

Moreover, this 4 inch carbon filter kit produces minimal noise with very high airflow rate. The ETL recognized components and superior quality carbon are also great assurance if you are opting for this product.

WHAT I LIKED

  • Very powerful inline fan with low noise level
  • Exterior and interior mesh allows improved airflow
  • Premium quality filter manufactured from 1050+ RC 48 Activated Carbon
  • Sturdy ducting and two stainless clamps which are strong and flexible for heavy duty use
  • PET core in between bordered by fireproof aluminum which can withstand high temperatures

WHAT I DIDN’T LIKE

  • Might be tricky to set up initially
  • May create slight noise during use

2. iPower Inline Fan Filter Ducting Combo

KEY FEATURES

  • 4″ Carbon Filter
  • 8 Feet Ducting
  • 190 CFM Duct Inline Fan
  • Bearings are permanently lubricated
  • 2 years warranty

As a carbon filter and fan kitcombo, this device by iPower is also a great choice for unwanted odor and heat removal. While it removes all unpleasant smells, it also eliminates any harmful gaseous substance that can harm your plants.

It has a size of 4 inches with a high airflow rate of 190 CFM. The highly efficient charcoal filters made from 1050+ IAV Australia Charcoal is very effective in its filtration mechanism.

The flame-retardant coating with corrosion resistant body parts also makes this 4 inch inline fan and carbon filter combo quiet a catch for many of the users.

WHAT I LIKED

  • Comes with a free pre-filter and two pairs of stainless metal clamps
  • Includes fire-resistance coating for high temperature endurance as well as corrosion resistant wire helix for longevity
  • 1050+ IAV Australia Charcoal for high absorption
  • Manufactured with high-quality material with zero-noise mechanism or vibration

WHAT I DIDN’T LIKE

  • Heavy and hefty in size
  • May require two people for set-up initially

3. BloomGrow Grow Tent Air Filtration kit

BloomGrow Grow Tent Air Filtration kit

KEY FEATURES

  • 6” Inline Fan
  • 6” Carbon Filter and Ducting
  • Included Fan Speed Controller
  • 24 Hour Timer Outlet+Thermometer
  • Used Coal Based activated carbon

BloomGrow6” Inline Fan Carbon Filter includes the whole package of everything you might expect in a carbon filter combo.

This filtration kit comes with a whole package of carbon filter ducting, fan speed moderator, a timer outlet as well as a thermometer ventilation system. The eco-friendly activated carbon is also a great addition.

The filter has a size of 6 inches, with a max power outage of 1800 watts. With a carbon layer of 1.5 inches and the durable zinc-anodized steel housing mesh, this product comes with the latest quality components.

Fan Speed Controller along with three speed control dialoptions also leaves a lot of room for flexibility and convenience.

WHAT I LIKED

  • Included a pre-filter
  • Life expectancy of 1.5 years
  • Low noise and hassle-free installation
  • High absorption rate of intaking unwanted gaseous substances
  • Fan speed controller can be used to regulate the speed in three options
  • Digital Thermometer Hygrometer to control temperature and humidity

WHAT I DIDN’T LIKE

  • May create slight noise in some of the units
  • Can be a little tricky to set up the timer initially

4. iPower Fan Filter Ducting for Grow Tent

iPower Fan Filter Ducting for Grow Tent

KEY FEATURES

  • 6 Inch 442 CFM Inline Fan
  • 6 Inch Carbon air filter
  • 25 Feet Combo
  • Variable Speed Controller
  • Rope Hanger for Grow Tent Ventilation

Made with quality components for efficient cleansing of air particulates, the iPower 6 Inch 442 CFM Inline Fan Carbon Filter just might be the carbon filter you have been looking for.

High airflow rate of 442 CFM provides rapid circulation that removes the most stubborn gaseous substances. Composite fan blades along with the stable and durable center hub reduces noise and vibration for hassle free usage.

Furthermore, it is also very easy to setup, and made from environmentally friendly parts. Flame retardant and corrosion resistant features are also great addition to the key attributes of this filter.

WHAT I LIKED

  • Zero-noise mechanism and no vibration
  • One control switch for 3 speed settings: low, medium, and high
  • 1050+ IAV Australia Charcoal is one of the world’s most absorbent carbon
  • Includes fireproof coating with high-temperature endurance
  • Corrosion-resistant wire helix for longevity
  • Includes free pre-filter and two pairs of stainless metal clamps
  • Bearings are permanently lubricated

WHAT I DIDN’T LIKE

  • May produce some heat in some units during use

5. PrimeGarden Fan Air Filter Ducting Combo

PrimeGarden Fan Air Filter Ducting Combo

KEY FEATURES

  • 8 Inch Inline Fan
  • 8 Inch Carbon Air Filter
  • Coal Based Activated Carbon Air Filter
  • Pre-filter Included for Hydroponics
  • 1xChangeable Velcro Pre-filter
  • Lightweight with easy installation

PrimeGarden 8 Inch Inline Fan Carbon Air Filtercan add as a great treat to your indoor grow tent, providing you with some of the most user-friendly and convenient features that you can have in such a device.

The carbon layer has a thickness of 1.5 inches, and it is made from eco-friendly components and parts. It is high durable with ceramic coating which ensures long life expectancy.

Another appealing factor of this product is the composite fan blades and center hub which ensures minimal noise and vibration.

With high efficiency andimprovedIodine Adsorption Value, along with the hassle-free maintenance, you cannot go grow with this carbon filter combo.

WHAT I LIKED

  • Very high temperature endurance
  • High absorption and performance with thick carbon layer
  • Inner and outerzinc-anodized steel housing mesh for increased air flow.
  • Made from activated carbon, which is environmentally friendly
  • Life expectancy of up to 1.5 years

WHAT I DIDN’T LIKE

  • May produce slight noise in high speed

What is a Carbon Filter and How does It Work?

Like the name clearly suggests, a carbon filter (or activated charcoal carbon filter) is an air exhaust system for controlling odor or aroma of your growing cannabis plants. Sure, you may be enjoying the smell of your plants, but you wouldn’t want that odor to leak outside your grow room. Would you?

By definition, a carbon filter is an elongated tube encased with metal and whose inner part is lined with activated charcoal (aka carbon).

Odor filters for grow tents are typically made out of porous materials, such as beds of activated carbon (charcoal) and polyester or any other spongy fibers.

If properly installed as part of an extraction system in an isolated space (such as grow room, grow tent, greenhouse, etc), a carbon filter can serve multiple purposes.

First, it prevents the smell of your marijuana from leaking outside of your grow room. And secondly, it hinders the odor from extending out of the grow room and lurking around your home.

A carbon filter is considered the most effective method of controlling cannabis smells, and it never changes the smell of your weed plants.

So, how does a carbon filter work?

Carbon filters contain odors and decontaminate the air through a process called adsorption. The process of adsorption takes place when molecules latch onto the outside of a surface, as opposed to absorption when they’re soaked into it.

Like I mentioned, carbon filters use the activated carbon, whereby the more porous the carbon, the better the extraction. The filters inside are formed by chemically and thermally treating charcoals, and turning them into activated carbon.

Activated carbon contains millions of pores, which help extend the surface area to 2000-4000 m2 per gram. Smelly particles and volatile organic compounds (VOCs) are drawn onto its surface to ensure better odor management.

A highly porous carbon increases the amount of surface available for impurities to attach onto when contaminated air passes through the filter.

Activated carbon comes in the form of thin or thick packets for filtering the air. You’ll need to insert it into the main purifying unit, such as a HEPA air filter (most recommended) or an air purifier.

As contaminated air passes through the main filtration unit, the activated carbon inside the unit absorbs the impurities. The air exiting the unit comes out of the filter purified and clean.

It’s best to use the activated carbon in conjunction with a HEPA filter. That way, you can easily restrain larger particles like lint, pollen and dust from coming into contact with it. The HEPA filter provides better performance and lasts longer.

Reason to Use a Carbon Filter in Grow Tent?

There are several benefits associated with using a carbon filter in grow tent or grow room. If you’re a cannabis grower, you probably know that keeping the cannabis aroma under wraps is no mean feat.

Worse still, perhaps you aren’t willing to let your neighbors know about your indoor weed growing “hobby”. And that’s where a carbon filter for a grow room comes into the equation.

Carbon filter for grow rooms/tent work like a magic bullet when it comes to trapping the smelly particles from the air, thus promoting your privacy. It also takes the impurities out of the air so your plants can enjoy clean, fresh air they need to thrive in your grow tent.

See, your plants not only need the right temperature to thrive. They also need the humidity, nutrients, and fresh air in correct proportions. A carbon filter eliminates such impurities as air-borne pathogens, which can cause diseases to your plants and ruin your grow yield.

By using activated carbon, you’ll improve your ventilation system, enabling your plants to breathe freely and eventually blossom. Other than that, grow room carbon filters are the least expensive of all air filtration systems available for grow rooms.

Investing in a high quality Air Carbon Filter is a sure-fire way to keep your electricity bill down. What’s more, carbon filters are pretty quick and easy to setup.

What Size Carbon Filter do I Need (Carbon Filter Size Calculator)

The right carbon filter size is ideally one that complements your fan’s cm3 requirements. You can use the carbon filter size calculator to determine the requirements of your application right off the bat.

Alternatively, you can use a simple length x width x height/3 calculation. From this formula, you’ll get the amount of air (cubic feet per minute, CFM) you’ll need to ventilate your space and facilitate a 3-minute air exchange (your space will exchange contaminated air with fresh air in every 3 minutes).

And, again, you’ll need to match the number you get to your filter.

Take a look at this example.

Let’s assume you’ve got the following measurements:

Room size: 10ft x 12ft x 8ft =960 cubic feet

960 cubic feet/3 minutes=320CFM.

The 320CFM is the minimum recommendable CFM that allows for air exchanges every 2-3 minutes (20-30 times per hour).

You can use the same formula for recirculating systems, but this time you’ll have to divide by 1.5 instead of 3. This provides a high cycle rate while ensuring maximum air purification with each pass through the filter.

Anyways, after determining the size of carbon filter to use, it’s time to figure out the fan size to pair with it. Here, you’ll need to measure the length, width and height (in meters) of your growing environment.

Multiply the length, width and height to get the cubic meter volume. Then multiply the figure you get by 20 or 30. The figure you get is the correct size of fan you need to use to facilitate air exchanges up to 20 or 30 times per hour (the recommended number; other factors may come in to play)

To allow for adequate ventilation, we recommend getting a fan that’s slightly above the figure you calculated. You also gotta factor in a 10-25% decrease in air flow caused by the resistance of transiting through the carbon filter chamber.

Pro Tip: If you’re using an exhaust system, steer clear of fans that exceed your filter’s exhaust rating.

How to take care of your carbon filter?

Taking care of activated carbon filters is all about removing accumulated debris that bars air from flowing through the entire filtration unit. Most carbon filters work optimally within 2-3 weeks of installation.

However, that’s not to say they’re unable to adsorb smelly odors 60-90 days after initial setup. Your filters can last longer and improve their efficiency if you spare a few minutes to maintain the filter housing, too.

How to take care of a dry carbon filter

If you’re using dry filters, take the charcoal filter out of its filter housing. Then, connect a crevice tool attachment to the hose of your vacuum.

Start by vacuuming one side of the filter in a side-to-side (horizontal motion) to eliminate dust and grime.  It’s best to start vacuuming from the top of the filter, working your way toward its base. Do the same for the other side.

Make sure to vacuum the filter’s housing as well. Some filter housings have an intake or outgoing air grate, vent or grille. If yours is of such type, use a damp and lint-free microfiber cloth to wipe all of its surfaces.

Then grab another cloth and dry with it thoroughly. Once done, put the filter back to its housing.

How to take care of a wet filter

Take the charcoal filter out of its housing and place the filter in a bucket of aquarium water or cool distilled water. If using an aquarium, soak the filter for about 5 minutes.

Then, while the filter is still submerged in water, swish it around for 3-5 minutes to dislodge the debris from its surface.

Discard the dirty water, and run aquarium water (or fresh distilled water) over the filter for close to 30 seconds. Lastly, put the charcoal filter back to its housing.

Never use the carbon filter beyond its lifetime

Of course, you shouldn’t expect a carbon filter for grow tent to neutralize odor forever. These devices have a certain lifespan when they perform at their best.

For proper odor management, you’re encouraged to change the carbon filters after a given timeframe. For instance, regular carbon filters may work optimally for 1-1.5 years. We also recommend, don’t go to cheap carbon filter for grow room or grow tent or grow box- any growing spece.

Even so, it’s best to watch out for the durability of your carbon filter at checkout. Some models are poised to exceed this timeframe, while others simply don’t go past one year.

Pro Tip: As a rule of thumb, you’re advised to swap out your carbon filter after 18-24 months, or as soon as the carbon gets saturated and loses effectiveness in filtering air. Also remember to provide adequate air flow so that the air can easily pass through the filter and heighten the air filtration performance.

Features to Look for in the Best Carbon Filter?

With a ton of options on offer, choosing the best carbon filter for grow tent can take a bit of digging. To make an educated purchase decision, the following is a rundown of the features to look for in the best carbon filter for grow rooms/tent.

Durability: How long can your carbon filter last? This is entirely dependent on the material used to construct the carbon filter. Steer clear of cheaply made filters that only last a couple of months, and opt for sturdy carbon filters made with premium galvanized steel or aluminum materials.

Although they might be expensive, they’re sure to last up to two years without acting up, which will be worth your investment in the long run.

Quality of carbon: You should expect to find carbon (activated charcoal) inside the filters for scrubbing contaminants from the air. Is the carbon of high quality? And where is it sourced?

The best grow tent carbon filter should come with the highest quality charcoal or carbon. From our experience, charcoals obtained from virgin Australian beds are the best in adsorbing odors and chemicals.

The best quality carbon has a high adsorbent rate due to more carbon present, and will certainly cover a huge space. Before you choose a carbon filter, try to figure out the volume of charcoal used, degree of activation, particle sizing, nature, and source.

Thickness of carbon:  The thicker the carbon, the greater the adsorption rate and elimination of foul odors. A thicker carbon actually makes the filer more effective in terms of odor control. Aim for a thickness of at least 50mm, such as the 6inch AC Infinity Air Carbon Filter which boasts 60mm thickness.

As expected, carbon filter models with thicker carbon boast of a higher price tag. The good news is that their effectiveness is on a higher level.

Versatility: Does your carbon filter have the dual function? A multifunctional filter offers the best bang for your buck, because you can use it on inline or exhaust fan. A good example is the G HYDRO 6 inch Carbon Filter, whose versatility is unbeatable.

As much as you wish to save on cash, I recommend opting for filters with dual role. This key function improves versatility and extends the life of your filter.

Pre-filters: Most top-rated grow tent carbon filters now feature pre-filters for reducing particles like dust from coming into contact with the filter. You can put these pre-filters outside of your carbon filter to remove sediments from your grow room.

Carbon filters that come packaged with pre-filters are longer lasting than those lacking them. They aid in eliminating larger contaminants that would otherwise get into the carbon filter.

Portability: The more compact a carbon filter is, the lesser the noise and vibration it discharges during operation. Compact carbon filters are also considered better at scrubbing odor and smell. The most portable option in our list is the CoolGrows 4inch Air Carbon Filter, which has only 6lbs.

Plus, transporting the best compact carbon filter for grow tent into the carbon granules is a walk in the park. Contrary to those with air pockets in between, this type of filter catches odor more efficiently, allowing you to enjoy odor-free environment.

Carbon filter-fan combo: Premium quality carbon filters for grow tents come with a filter-fan combo. These choices take minimal effort to install and adjust. And the fan and filter combination is designed to complement each other for augmented air scrubbing performance.

Additionally, higher-tier models not only come complete with the fan-filter combo but also speed controlling devices. Such a package is an ideal 360-degree ventilation solution for your grow system.

Frequently Asked Questions

Do I need a carbon filter in my grow room?

Good question. Well, you definitely need a carbon filter in your grow room if you care about eliminating odor and preventing ill-fating microbes from entering and infecting your plants. Grow room need strong ventilation due to intense smells and odors discharged by plants inside it.

As a matter of fact, some cannabis varieties emit extremely strong odors that can make your house smell like an intense hotbox. For best odor management in such scenarios, carbon filters are a life saver.

Like we discussed earlier in this post, each carbon filter has layers of activated carbon beds, with each particle offering a surface area full of pores. One gram of activated carbon contains up to 2000-4000 m2 of surface area, where pollutants, odors, pathogens, and allergens latch onto as air passes through the filter system.

This surface filled with pores traps pollutants and allergens from air through a process called adsorption (not absorption). The carbon beds adsorb various odor-creating gas molecules, resulting in a pollutant-free, odor-free grow tent.

What size carbon filter for 3×3 grow tent

A 4-inch air carbon filter is enough for odor control in a 3×3 grow tent. It’ll be able to scrub the air from your grow tent about 2-3 minutes per minute.

What size carbon filter for 4×4 tent

4 inch carbon filter is enough for 4×4 grow tent . A 4-inch carbon filter easily removes all the odors from the air before they’re expelled from the vent.

Nevertheless, if you’re running a High-Pressure Sodium (HPS) grow light, you might want to consider using a larger 6-inch carbon filter with a high CFM fan. A larger carbon filter and fan helps cool down the vent.

What size carbon filter for 5×5 tent

6 x 12″ or 8 x 12″ carbon filter is ideal for 5×5 grow tent. But you would need a decent carbon filter and a strong fan for pushing hot air out of the grow space. 

Your choice will be based on the amount of space available for an intake filter. Also, make sure you opt for fans or coolers that generate at least 400 CFM of air.

Furthermore, it’s best to use High-Pressure Sodium lights (HPS lights) with a rating of at least 1000 watts. HPS lights appear yellow in color but have yellow and red color spectrums, which are helpful for flowering plants.

Of course, no one said you’re restricted to using HPS lights for flowering plants only. Studies have shown the effectiveness of HPS lighting for vegetative plants as well. And you may still opt to use high yield LED grow lights if you so desire.

What size carbon filter for 4×8 tent

A 6-inch carbon filter would be suitable for taking care of the unpleasant smell in a 4×8 grow tent.

However, in some cases, you might want to consider using an 8-inch carbon filter 4×8 grow tent, depending on your plants and other factors.

Generally, a 6-inch option would meet your specifications when it comes to scrubbing the air. Nevertheless, keep monitoring the growth of your plants regularly to determine if the efficiency of the fan is reduced.

What size carbon filter for 10×10 room

8″ or 10″ carbon filter is suitable for 10×10 grow room, actually depends of your plants and other grow tent ventilation system like light, fan etc.

More often than not, a 10-inch carbon filter (at least 1130m3/hr) can completely banish any unwanted odors from a larger 10×10 grow room. A larger filter of this caliber is designed to ensure maximum air flow, durability and flawless performance.

Nevertheless, it might emit a lot of noise during operation. So it’s best to opt for options that include the noise-reducing technology.

Final Remarks

From this review and guide, we believe you’ve already chosen the best carbon filter for grow tent based on your needs and preferences.

As you can see, the current market presents many sizes and models of carbon filters. Most of these models are a far cry from each other, and you gotta take into account the size of your grow tent when making your purchase.

Anyways, if you’re still in catch-22 regarding what to opt for, why not consider the iPower 4inch Air Carbon Filter? It doesn’t cost a fortune, and is sure to keep your weeds’ smell under control and guarantee your privacy.

At the end of the day though, your choice should be fully dependent on the size of your grow room. You may want to choose any other carbon filter for grow room listed above according to what you’re targeting to achieve.

Happy shopping!

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