Carbon filters are currently the most popular methods of handling odors around indoor grow rooms and keeping prying noses away.

A carbon filter can be a highly effective method that can eliminate over 90% of smells, assuming that the air filter fits your fan properly and it is big enough for your room.

If it is the wrong size, it is not going to be very useful. This may be a big problem for growers who are new to growing rooms.

There are numerous carbon filters on the market. Therefore, choosing the best carbon filter for grow room may not be a walk in the park.

PRODUCTSIZE (INCH)CFMPRICE
Hon & Guan6No Info
View on Amazon
TopoGrow6450
View on Amazon
iPower4200
View on Amazon
TerraBloom6550
View on Amazon
Vivosun4350
View on Amazon

Top 5 Carbon Filters for Grow Room

#1 Hon & Guan 6-Inch Carbon Filter

Coming first in our list is the Hon & Guan carbon filter. It comes highly recommended by most users because of its unmatched performance.

The main structure is made of galvanized steel, which is by far more durable compared to aluminum.

The base and filter flange of the main structure are switchable. The outer and inner mesh have sufficient open area for superior airflow.

What is probably most impressive about this unit is the reversible smell filtration. You can use it as an exhaust or intake filter. You can use it to filter, purify, or move air.

This unit is engineered for enclosed grow rooms. It will soak and get rid of unwanted smells. It promotes better plant health by ensuring that the air is always clean.

There are two ways you can install this filter. You can install it as an intake filter by placing the pre-filter outside or you can install it as an exhaust filter by placing the pre-filter inside.

The Good

  • Switchable base and filter flange for longer use
  • Can be used as an exhaust or intake filter
  • Inner and outer mesh offer a more open area for superior airflow
  • Zinc treatment is resistant to chemical corrosion
  • Galvanized steel air odor control scrubber is highly durable

The Bad

  • CFM rating is not provided
  • Could have better connection pieces

#2 TopoGrow 6-Inch High CFM Carbon Filter

The TopoGrow Carbon Filter is one of the finest. It comes with a quality design made of pad and carbon charcoal.

This unit features a zinc anodized steel casing that is highly durable than other materials. The casing is highly resistant to chemical corrosion.

Whether you need exhaust or intake air cleansing, the TopoGrow is what you need. Your plants will greatly enjoy the odor of free air.

This unit has a maximum scrubbing of 450 CFM, with an iodine adsorption rating of 950, which is highly efficient.

It has a carbon layer thickness of 1.5 inches with an operating environment temperature of -20 to 65 degrees Celsius. Its maximum endurable temperature is 400 degrees Celsius.

This unit has a reversible filter base and flange, which extend the filter’s life. Not to mention the exceptional removal of pungent odors and smells for better privacy.

The Good

  • Superior air flow scrubbing of 450 CFM
  • Zinc anodized steel casing is highly durable
  • Changeable Velcro pre-filter helps to remove impurities
  • Reversible filter base and flange improves the filter’s life
  • Outstanding pungent odor control for superior privacy

The Good

  • Pre-filter may fail to perform admirably

#3 iPower 4-Inch Air Carbon Filter

Are you searching for a professional grade filter? If you are, look no further than the iPower 4-Inch Carbon Filter.

The iPower Carbon Filter has a cap that is engineered from high-quality aluminum material that has superior lasting effects and maximum strength.

What’s most impressive is the iPower four-layer construction that starts with the inner mesh, charcoal bed, outer mesh, and pre-filter on the outside.

The inner, as well as outer mesh, provide a larger open area for increased airflow. The pre-filter; however, needs to be replaced every six months.

This unit features special virgin carbons obtained from the Earth’s pressurized sources. These carbons have a superior odor removal performance.

The iPower has a reversible base and flange. You can easily flip the entire filter upside down to remount the base and the flange for the second year of scrubbing.

The Good

  • High-quality aluminum cap has superior lasting effects
  • Four-layered construction guarantees effective performance
  • Increased airflow, thanks to the inner and outer mesh design
  • Virgin carbon is very effective at removing pungent odors
  • Reversible base and flange increases usability

The Bad

  • Pre-filter has a shorter lifespan

#4 TerraBloom Activated Charcoal Filter

It may be the fourth favorite in our list, but the TerraBloom is built to perform. It is made of high-quality RC-48 charcoal carbon obtained from Western Australia.

The carbon bed incorporated in this unit is machine packed and 46 mm thick. Not to mention that it is integrated with very small granules for better filtration.

You will like the aluminum construction that is very lightweight. The aluminum flange and base come pre-installed.

TerraBloom is probably the only brand that will provide you with two machine washable pre-filters. They are available in black as well as white colors.

The filter has an airflow rating of 550 CFM, which can be used for up to twenty-four months. It is capable of filtering plant-based allergens along with other foul smells.

The Good

  • Lightweight and easy to install aluminum construction
  • Built with high-quality activated virgin carbon
  • Thicker carbon bed for superior smell control
  • Two machine washable pre-filters for effective air cleaning
  • Very effective at removing plant-based allergens

The Bad

  • May require ducting to attach to a fan

#5 Vivosun 4-Inch Air Carbon Filter

Coming last in our list is the Vivosun Carbon Filter. This one also features virgin Australian activated charcoal that delivers reliable airflow filtration.

It is incorporated with RC 48 (1050+) carbon that is very much capable of capturing more air contaminants than conventional filters.

Unlike traditional carbon filters, the Vivosun comes with reversible base and flange. This simply means you can flip the bottom and the flange to extend the filter’s life by a year or so.

The four-layered construction includes an outer and inner mesh. The mesh provides a larger open area for superior airflow. The design is also incorporated with a Velcro pre-filter.

You can use the Vivosun as an exhaust or intake filter in different configurations, such as with ventilation ducts, air exchange fans, and six-inch inline fan.

The Good

  • Outer and inner mesh allows for effective airflow
  • Reversible base and flange provides longer life
  • Can be used as an exhaust or intake filter
  • Carbon particles used to eliminate more air contaminants

The Bad

  • May not be suitable for a larger grow room
  • Pre-filter has a shorter life

What to Look For In a Carbon Filter

Grow Room Size

What size carbon filter do you need for your grow room? This is the very first question that you have to ask yourself.

Start by calculating the volume of air used in your grow room. For example, if your grow room is 10 by 12 feet, and your ceiling is 8.5 feet high. The volume is 1020 cubic feet.

That’s about 29 cubic meters for any sensible metric people out there. We are talking about the volume of air used for actual growing.

If you have a room this size, but you are only using half of it to grow your plants, you could divide the volume in two.

Similarly, if you are growing in a tent, it is the air volume of the grow tent itself that you need to take into as far as your calculations go.

Fan Size

Then go ahead and calculate the size of the extraction fan you need. You can use a fan speed controller to give yourself some wiggle room.

An indoor grow room full of mature plants would most certainly have a high demand for Co2 and transpires more moisture into the air.

This is when you actually need to exchange your grow room air once every sixty seconds. Young plants don’t need so much air exchange.

In our example, we need to exchange 1020 cubic feet of air each minute. Therefore, you would need a powerful exhaust fan, such as a 10-inch hyper fan that can shift 1065 CFM.

Air Flow Requirements

How do you know how much CFM you need? First, you have to understand what CFM is to be able to answer this question.

Well, CFM refers to cubic feet of air per minute. To compute the ideal CFM that your carbon air filter must have, you need to multiply the height, length, and width of your grow space.

You can use this number to shop for a suitably rated intake fan. For instance, a CFM of about a third of the grow space volume.

A carbon filter’s resistance would require you to increase the computed volume by twenty percent since the fan needs to be slightly stronger to overcome the resistance.

The simplest way to determine the ideal CFM is by using a CFM calculator. The dimensions of your grow room are very crucial when determining airflow requirements.

If we use a CFM calculator, our room size example would require a carbon filter with a CFM of 490, if you will be using a single grow light.

What is contained in the Carbon Filter?

Activated carbon refers to charcoal that has been exposed to high temperature and steam in the absence of oxygen.

Activated carbon has a microporous structure that provides a very large surface area to weight ratio that facilitates surface adsorption.

The performance of a carbon filter is determined by the quality as well as the amount of carbon that is present, by the activation process, by the air flow pattern, and by the moisture in the air.

A given amount of carbon can only absorb a specific amount of compounds. Therefore, the more carbon present, the heavier or denser the filter would be and the longer it will work.

All absorption ratings are based per gram of carbon. More weight equals more absorptive capacity.

The adsorption capacity and the rate of removal varies greatly with the carbon used. The activated charcoal efficiency is a function of various parameters.

The parameters include the degree of activation, nature, source, particle sizing, and volume of charcoal used.

Pre-Filter Included

The life of a carbon filter can be extended by using a less expensive pre-filter to remove some of the impurities from the grow room.

Most top rated carbon filters for grow room come with a pre-filter to remove sediments.

Those with a pre-filter in a separate canister are superior to those with carbon and pre-filter sharing a container because they are easier as well as cheaper to maintain.

Such sediment filters will pick up many of the larger contaminants that would otherwise pass right through the carbon, making this combination a very good idea.

High Performance Fan

The other important consideration you will have to make is choosing which high performance fan  your carbon filter uses.

The most popular size for most grows room sizes is a 10-inch hyper fan. This type of fan is compact with more CFM per watt than conventional fans.

You should look for a fan with a superior CFM than your carbon filter in order to overcome the resistance that is normally associated with carbon filters.

The ideal fan should have a rating of at least 1065 CFM. This rating is ideal for small (324 cubic feet) or large (1020 cubic feet) rooms of different sizes and so on.

Final thoughts

Grow rooms are awesome, but they need to be ventilated correctly. The most important thing is to extract the hot air away not just out of the tent itself, but out of the room.

These days most grow rooms have their extraction fan positioned in the roof. This is ideal because you can remove the hottest air, and it makes for easier positioning of the extraction fan.

With that said, you can ensure your plants breathe purified air by attaching a high-quality carbon filter to your extraction fan system.

Choose one of the reviewed top rated carbon filters for grow room from our list. The aforementioned buying tips should also help you make a profound choice.

About The Author

Leave a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Scroll to Top