5 Steps To Setup A Grow Tent Carbon Filter

As we all know, a carbon filter is an extremely critical element in any grow tent. Setting it up is important yet, it can be tricky for newbies. In this article, we’ll discuss what are the aspects you need to be aware of when setting up your carbon filter setup, what ventilation methods are available, and how to set up a carbon filter in a grow tent step-by-step.

With this guide, you’ll be able to set up your carbon filter and begin growing indoors confidently.

Grow Tent Carbon Filter Size Guide

Choosing the right carbon filter size for your grow tent is a key step before going ahead and setting up your indoor growing setup.

Below is a brief size guide to follow before purchasing any carbon filter.

Grow Tent SizeCarbon Filter Size Best Carbon Filter
2×24-InchVIVOSUN 4 Inch Air Carbon Filter
3×34-InchVIVOSUN 4 Inch Air Carbon Filter
4×44-InchVIVOSUN 4 Inch Air Carbon Filter
4×88-InchAC Infinity Air Carbon Filter 8″
5×56-InchiPower 6 Inch Air Carbon Filter
10×108-InchAC Infinity Air Carbon Filter 8″
Grow Tent Carbon Filter Size Guide

The above data should get you going. However, other factors impact the carbon filter size. You can find more about it in a detailed article I wrote.

In certain situations, growers tend to get a carbon filter with a size larger than the required one for their grow tent to eliminate as much smell as possible. Although this technique is effective, it increases the exhaust fan’s electricity costs and occupies a lot of internal growing space inside the tent.

If you wonder which carbon filter is going to suit your grow tent, check this guide on the best available carbon filters on the market.

5 Key Steps To Setup A Carbon Filter In A Grow Tent

Step 1: Prepare The Carbon Filter

Unpack the carbon filter from its box and remove any of the package wrappings. Check that there are no package stuffings inside the carbon filter hollow center to make sure that air will flow smoothly.

Install the prefilter on the outer surface of the filter.

Required Items

  • Carbon filter
  • Prefilter

Step 2: Connect Carbon Filter To Exhaust Fan

You need to connect the carbon filter to the exhaust fan on the ground before hanging any component. To have a flushed flange connection it is best to use a fast clamp.

The fast clamp will help you secure a leak-proof connection regardless of the size differences in the flange and the duct.

To control the fast clamp fitting, all you need is an Allen key.

Required items:

  • Exhaust Fan
  • Fast Camp
  • Allen Key

Step 3: Hang The Filter-Exhaust Unit

Once you are done connecting the filter and exhaust fan together, hang the filter-exhaust unit on the grow tent frame using the rope clip hangers.

Make sure that the weight is distributed evenly across different support bars to gain more strength and stability.

It is best that the carbon filter is hung at the corners or the side of the grow tent to give more space in the center to the growing lights.

Required items:

  • Rope Clip Hangers

Step 4: Connect The Fan To The Outside Vent

In this step, you will connect the exhaust fan to the outside vent using a PVC duct. Secure the duct in its place with heavy-duty duct tape to ensure that air will flow outside of the tent and not inside the tent again.

Step 5: Run And Test

Plug in your exhaust fan and run a simple smoke test to make sure that the filter is running efficiently.

Place a burning piece of paper beside the carbon filter while it is up and running. Go check if there is any leak present in the duct connections that you made in the previous steps.

If you find the filter sucking in the smoke with minimal to no smoke odor, then your filters operate successfully.

Exhaust Method

There are 4 main exhaust methods that we use as grow tent hobbyists.

Filter-Inside Fan Inside

This is the most used method among grow tent growers. In this method, both the filter and the fan are fitted using the grow tent frame.

In this setup, the fan is directly connected to the carbon filter, and the distance that the air needs to travel from the carbon filter to the exhaust fan is significantly reduced.

As a result, the exhaust fan works efficiently with minimum to no extra load on it.

Filter-Inside Fan-Outside

This filter system will have the carbon filter hung on the grow tent frame, while the exhaust fan is placed outside. The exhaust fan will usually get support from an external source.

In this setup, there is a duct that connects the carbon filter to the exhaust fan outside. The efficiency of this carbon filter system is hugely impacted by the length of the duct connecting the filter and the exhaust fan.

A short duct length will have minimal effect on the exhaust fan efficiency, while a long duct length will hugely reduce the output of the fan.

Filter-Outside Fan-Inside

Placing the filter outside is a trick that grow tent hobbyists do to save up growing space.

A carbon filter can take an average of 15% of the internal growing space of any grow tent.

In this setup, more growing space is utilized to grow more plants. However, pushing air through a carbon filter does not provide maximum efficiency for both the filter and the exhaust fan.

I wrote a detailed post that you can read discussing how to implement this method and what are the risks that arise with it.

Filter-Outside Fan-Outside

The method’s name already expresses itself. If you have a small grow tent that you want to use every internal inch of it to grow plants, this method is ideal for you.

Moreover, some growers use a carbon filter and an exhaust fan that is way bigger than the actual size recommended for their grow tent. Using larger-size carbon filters is one of the most efficient ways to eliminate odors in a grow tent

If you are interested in blocking odors in your grow tent, take a look at the grow tent smell-proofing cost breakdown that I did.

Type Of Grow Tent Carbon Filter

There are two main types of grow tent carbon filters that growers use nowadays.

Scrubbing Carbon Filter

As the name suggests, this type of carbon filter heavily depends on scrubbing and filtering the already existing air to be reused again by the plants. Air does not get exhausted outside of the grow tent.

Scrubbing carbon filters are the type of filters used in a grow tent with a closed-loop system. A closed-loop system is used when a grow tent operates with a supplemental CO2 system and helps to ensure adequate air circulation and filtration of the air.

This helps ensures that your plants can receive a steady supply of CO2 and help protect against the continuous fluctuations of certain growing conditions. Carbon filters are an essential part of this closed-loop system and help to keep the air clean and free of odors.

They are made up of multiple layers of activated carbon, which is a form of carbon with a large surface area. As air passes through the filter, these activated carbon particles adsorb odors, chemicals, and other particles from the air. This helps to keep the air clean and free of contaminants that could otherwise harm your plants.

Exhaust Carbon Filter

Exhaust carbon filters are the type of filters used in an open loop ventilation system where there is always constant exhaust air flowing out and fresh air flowing into the grow tent. Exhaust carbon filters work by drawing air from the inside and then passing it through a filter of activated carbon.

This carbon absorbs odors, chemicals, and other particles from the air and helps to keep the exhausted air free of stinky odors produced by the plants.

One of the perks of having an exhaust carbon filter is combining it with an inline fan to create negative pressure within the grow tent. This means that the fan is constantly pulling air out of the tent, while fresh air is drawn in from outside. This helps prevent any odors from leaking outside of the grow tent and also allows for more efficient air circulation.

Compared to closed-loop ventilation systems, exhaust carbon filters operating in an open-loop grow tent are relatively easy to maintain, especially for newbies with little to no experience.

Most filters come with instructions on how to install them, and they can usually be installed in a few minutes. As for maintenance, the filter should be cleaned or replaced regularly, you can check how long a carbon filter lasts in a grow tent to get a better understanding.

Is It Better To Push Or Pull Air Through A Carbon Filter?

Carbon filters are an essential component of any indoor growing environment that any grower must have. With the different ventilation methods and designs that arise, growers ask a serious question: is it better to push or pull air through a carbon filter?

Generally speaking, pulling air through a filter is the optimal technique because it creates a negative pressure system, which helps provide an uninterrupted flow of air and helps to prevent any backflow. This also helps to ensure that the filter is working to its fullest potential. Additionally, pulling air through the filter will help to prevent any dust or other particles from settling on the filter, which can reduce its efficiency.

On the other hand, pushing air through a filter is also an option. It can occur in cases where the carbon filter is placed outside of the grow tent for several reasons. Putting the carbon filter outside would save any grower a lot of internal growing space that he can then use productively.

However, pushing air through the filter can increase the amount of resistance, which can lead to reduced airflow. Additionally, pushing air can lead to more particle build-up on the filter, which can reduce its efficiency.

Ultimately, pushing and pulling air through a carbon filter have pros and cons. It is important to assess the specific needs of your environment and determine which option and ventilation method works for you.


In conclusion, setting up a carbon filter in a grow tent is essential to maintain an odor-free growing environment. There are two common types of carbon filters, the scrubbing and exhaust methods, each with its own advantages and disadvantages.

Regardless of which method you choose, it is important to install your carbon filter with a secure pre-filter and hang the carbon filter and inline fan assembly in the desired location with the least duct length possible. With the right setup, you can ensure that your air is clean and odorless, allowing you to get the most out of your grow.

Leave a Reply

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

Recent Posts