What Size Carbon Filter For Grow Tent – [In Depth Guide]

Growers! Are you ready to start your indoor gardening projects? Wait there is a stinky odor—Oops! Probably it’s coming out of your grow room. What’s the reason?

Your Carbon filter is not working. Why?

You did not size it according to your grow tent needs.

What carbon size filter for grow tent? There are different sizes of carbon filters available according to the volume of grow tents and CFM. You can determine the internal Volume and CFM by applying a mathematical formula. Other factors like space available for placing the filter, temperature and lights installed also play a secondary role in sizing filters.

Suppose you are using lights with more watts and pressure then there would be more heat. In this scenario, you would have to install a filter of 20%more CFM value than you calculated. This and more other Infos related to sizing hacks are yet to reveal. Keep on reading to know more!

How To Select The Right carbon Filter

How to pick the right size carbon filter is not just a trick! It requires a bit of mathematics and common sense both. Here are a few tips that will make you sharp and wise whilst selecting the right stuff.

  • First measure the area of your grow room and then match the filter that is suitable in this space.

To measure the volume, you can apply this formula


In some grow tents, height is not marked you can measure it by yourself 

  • After measuring Volume, it’s time to derive CFM that stands for cubic feet per minute. This CFM value tells how much air in cubic feet your carbon filter will clean out per minute. To determine CFM, you need to do maths again

You can measure it by dividing the volume of grow tent with number 3

               CFM=Volume of Grow Tent


Both volume and CFM will help you to decide what size filter fits your tent

  • For tents, with400CFM or above, Carbon filter of size range 6” or above is the perfect match
  • Similarly for 700CFM or above, Carbon filter of the size range 8” is suitable

Always read the label on the filter and make sure that you are choosing the right CFM according to your tent size. I would recommend you go on to buy a filter that is in the size range of 20% higher CFMvalue than you estimated. It will reduce risk factors.

Table of Carbon Filter Size According to  Grow Tent Size

SerialGrow Tent SizeCarbon filter Size Best Carbon Filters
14x44-inch filterVIVOSUN 4 Inch Air Carbon Filter
23x34-inch carbon filteriPower 4 Inch Air Carbon Filter Indoor Plants Grow Tent
35x56-inch or above




iPower GLFILT6M 6 Inch Air Carbon Filter Indoor Plants Grow Tent 
42x24-inchiPower 4 Inch Air Carbon Filter Indoor Plants Grow Tent 
54x88-inch filteriPower 8 Inch 750 CFM Duct Inline Fan with 8" Carbon Filter 
610x108-inch filter or 8’x24’Carbon filterHydro Crunch 8 in. x 24 in. Carbon Charcoal Air Filter

Things To Know Before Sizing Carbon Filter 

Growers! Wait and read this before placing your order for a carbon filter! If you have finally decided to put a filter to remove odor then think about its appropriate size. Keep these important points in your mind and then make the right choice

  • Size of the tent; Think whether your tent has enough space to accommodate a filtering device or not. For this do some maths given above
  • Temperature; Consider temperature in your area also and if it’s too hot then proper fanning would be a must thing along with Carbon filter
  • Setup installed; Size your filter according to your Setup demands. Sometimes growers set filters outside the tent and sometimes inside. So, choose size accordingly.
  • Calculate Internal Volume; Internal Volume in the cubic meter is perhaps the strongest clue to determine filter size. Calculate it by applying the Length x width x heigh formula.
  • Light; Filer size should be adjustable to your light demands. If you are using high-pressure lights then go for the increased range to get good results
  • CFM.This is another deciding factor that could help you to make the right choice by size. If CFM is greater than 700 then c filter would be more than 8incch or above.

What Size of Carbon Filter for 4×4 Grow-tent

For beginners, a grow tent of 4×4 is a perfect fit. It can accommodate 4 to 6 medium-sized plants easily. This tent size is relatively not big enough to hold a massive filtering device. So, a carbon filter of 4-inches is a good fit for this size to filter the air inside the tent. One more thing, for normal pressure sodium light 4inch filter, will work efficiently. If you plan to use High-Pressure Sodium light, you would have to change filter size from 4 inches to 6 inches. Because with high-pressure light, more heat will produce that increase the temperature and a 4-inch filter may not work in this scenario.

It is always suggested to choose to grow tent lights, fans, and filters according to tent size, expected temperature, and humidity level.

What Size Carbon Filter for 10×10 room

Ever dreamt of a large garden indoor? Sure, get 10×10 grow tents and grow desired crops with plenty of temperature control and space. Such a big area will need something special to clean out air from every kind of chemical and odor.

Carbon filter ranging from 8” is the perfect match for 10x10grow tent. Never choose any filter for this size having less than 200CFM. The lowest filter size for this tent should start from 8 inches. You can further go for 8”x24” activated filter options depending on your needs, heat source, and space.

Making the right choice at the right time using knowledge is essential. In this way, can save your money, efforts as well as time. So, always do a proper search before buying any product.

What Size Carbon Filter For 3×3 Grow Tent

Grow tent of 3×3 size fall in the category of mini tents suitable to grow 2-4 large or medium-sized plants. Here the internal area or volume is too small to hold big filters.

So, a carbon filter of 4-inch will do air cleaning and odor absorbing jobs efficiently in this 3×3 size tent.

However, if you are using high-pressure lights then it’s better to go for a 6-inch filter in this scenario. Otherwise, you may not be able to control heat.

Carbon Filter Size Calculator

Are you confused about what size you should select? Dont worry though— we have a mathematical solution to your problem. The first thing that we need to know before placing the order of the filter is to calculate the volume of the grow tent. Here is a formula that will help you to calculate volume then CFM 

Volume=Length x width x height

After volume, you can calculate CFM that is the amount of air per cubic meter cleaned in a minute.It can be determined by dividing the volume of the grow tent with number 3. The formula is written there.

CFM= Volume of grow tent         


In this way, you can calculate both values CFM and volume in a cubic meter that is essential to size your filter. This CFM value is written on the filter box. So, make sure that the filter you are purchasing has the right CFM according to the volume of your grow tent.

Related Articles: Do You Need Carbon Filter For Grow Tent

Where to Put Carbon Filter in Grow Tent

Before sizing, fix the point where you want to put your filter inside the tent.

Growers often place it near the floor if it’s too heavy. But after research, it is an approved fact that filters hanging along the inner side of the tent roof works efficiently well. If it is connected to fan it would help to draw hot air outside through ducting,

So, ideally, the filter should be hung along the roof. It would help to save your place for plants as well. For more tight tents, growers set the filter outside of the tent. Though this type of setup is possible but not recommended. There are safety risks attached to it

What Size Carbon Filter for 5×5 Grow Tent

Is your grow tent 5×5? Well, how would you size a carbon filter for it? The size of the carbon filter depends on CFM and inner space to place or hang the filter. For 5×5 tents, the estimated CFM will be above 400. Here carbon filter 6’x12” and 8”x12” sizes having 400 CFM or above will do a good job. Both have CFM greater than 400.

Carbon filter 6×12 has 450CFM whilst 8×12 has 460CFM.

If your grow tent is 5×5 then depending on light pressure you can choose either 6”x12” or 8”x12” size filters. If you feel more heat then 8”x12” will work more better in this scenario.

What Size Carbon Filter for 4×8 tent

Depending on other factors like light capacity and temperature, an 8-inches filter having 700CFM or above will be a good match here.

Phresh inline carbon charcoal filter of 750CFM  ideal for 4×8 tent setup. The estimated height of these tents is also 8. So, the internal volume is relatively larger 4x8x8 to accommodate an 8-inch filter easily. If you install a 6-inch filter here, it will also do the right job but nor perfect. Why not choose the ideal setup and go for an 8-inch filter and make your plants happy!

What Size of Carbon Filter For 2×2 Tent

This is the smallest size tent and is specially designed for beginners. These are absolute mini-minor structures but if you want to install filters here you can still do this.

Filter size for the 2×2 grows tent should be 4-inch as it is the last smallest version. Now it’s up to you how you would adjust it in your tent. The best way is to hang it over the inner wall of the roof so as to save some space for plantation. Hopefully, it will your make your atmosphere smell-free.

Bottom Line

Now it’s time to leave the Carbon filter sizing hacks. Though it can be tricky for those who don’t like maths. Do proper research and label reading of any product you are going to buy whether it is Carbon filter or Grow tent. I would suggest getting a full kit or Set up according to your tent size that may include everything fan, tent, filter and lights. If you go on with the kit, there would be less chance of mistakes. I hope you already know now that what carbon filter size for grow room.

We want to hear your experience about different sizes of filters with different grow tents. So, share anything about this topic in the comment box. Thanks to read on.Bye

Lisa Marshall

Hi, This is Lisa Marshall. Lisa has been working with farmers for over thirteen years. It is his passion, hobby and profession. To facilitate other gardeners from her experience, she has decided to start this website to share her gardening experience with her plant lovers.

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