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How To & Why Use Carbon Filters For Grow Rooms?

Indoor Grow Carbon Filter

Everyone is familiar with the skunky, herbal scent of marijuana. You might love the smell of freshly grown cannabis, but your landlord and neighbors won’t. No, this doesn’t mean you have to move to a secluded forest up the mountain to grow weed. You just need a carbon filter for grow rooms to help reduce the smell of marijuana plants

Want to know more about using one in your indoor weed garden? Let’s find out! 

What is a carbon filter & how does it work?

A carbon filter is precisely how it sounds, a filter that uses activated carbon. It works to get rid of unpleasant smells in the air that pass through. Along with odors, the filter purifies by absorbing toxins and other particles. 

Activated carbon, also known as charcoal, is highly porous, almost like a sponge. You can find this substance in all types of purifying products, not only marijuana. You can use it to filter water and air, and it’s commonly used in beauty products. 

It is possible to make activated carbon by burning various kinds of wood or fruit shells, such as coconut. The material is put in an oven and brought to 752 degrees Fahrenheit, then again to 1472 degrees. It’s treated with vapor to help open pores. You can purchase activated carbon in a powder or hard pellets. 

A carbon filter for grow room is usually a cylindrical shape, and inside it is the activated charcoal. A fan draws air into the tube; it’s filtered and then released without any odor or toxins. Filters come in many sizes, so depending on your indoor garden, you can choose accordingly.

Carbon Filter Grow Room
Carbon Filter for Grow Tent

What are the benefits of using a carbon filter for grow tent?

If you’re a new cannabis grower, you might be thinking you can skip this piece of equipment, but you’ll soon see that it’s essential. Maybe you like the smell of weed, but it gets old fast. 

Prevent the smell from leaking out

If you think about it, beer lovers have refrigerators full of their favorite drink, but it’s likely they don’t want their kitchen to smell like a college bar. You love smoking marijuana; however, living in the musky scent isn’t ideal. So, how do you get rid of the weed smell?

A growing weed air filter will significantly reduce the herbal odor from leaking out of your indoor garden. This is good for two reasons. 

The first being to stay out of trouble with the law. Even in legal growing states, the public can’t know you’re harvesting marijuana. A neighbor or landlord can call officials, and you might face a fine.

If you’re living with anyone under 21 years old, this is an even bigger problem because you must securely lock away all cannabis products. When your neighbors can smell it, you know that minors can too. 

The following reason is to keep you and your guests happy. You want to walk into your home after work to a clean scent. Guests might be bothered by the odor and not want to come back.

A carbon filter for weed will reduce any strong smells from escaping the cannabis growing area. 

Indoor Cannabis Plants Enjoy Proper Ventilation
Indoor Cannabis Plants Always Enjoy Proper Ventilation

Stop smells from leaking in

Marijuana is a sensitive plant, and many factors can influence how it grows. This psychedelic crop likes a warm and humid climate. This is the same environmental pathogens like. 

Air from the outdoors can contain bacteria, mold, viruses, or fungi that’ll harm your cannabis crop. Without proper growing ventilation, these pests can stick around and cause bud rot and damping off. A cannabis carbon filter will help to purify the flow coming into the indoor garden. It’ll ensure your weed plants stay healthy and make them less prone to disease. 

Where to put a carbon filter in the grow room

You should place the carbon filter for grow room where the airflow comes from. It could be a window, an interior air conditioner, or a vent. 

Place the carbon filter right next to the breeze, so any air coming in or out goes through the activated charcoal. This is when the size comes into play. You need to buy a model that’s appropriate for the vent or window size. 

The carbon filter needs to be secure and sealed correctly to ensure it’s working perfectly. If air can get in or out without passing through, you’ll still have an odor problem. 

Carbon Filter For Grow Room
Remember to seal the carbon filter correctly or you’ll still have an odor problem

How to create and install a carbon filter (Step by step guide)

What is the best carbon filters for a grow room?

Carbon filters can be bought online or at a store. The problem with these is that it’s hard to customize them to fit your space. Also, if you’re on a budget, making one can save you a buck or two. A bonus, you’ll have a weekend project to keep you occupied while high. 


Before you start building your carbon filter for weed, you’ll need to have all the materials in order. You’ll be able to use things around your house and buy anything extra at your local hardware store. 

The basic materials you’ll need are:

  • Activated carbon
  • Aluminum screen and/or chicken wire
  • PVC cap
  • PCV adaptor
  • Ventilation hose
  • Duct tape
  • Quilt or blanket
  • Tall laundry basket with lid

The procedure

Now that you have all of your supplies, it’s time to start building. We’ve put together a step-by-step guide for a basic carbon filter. These can be altered according to your space or other preferences. 

  1. Create a tube out of aluminum screen/chicken wire that’s the same diameter as the PVC cap. 
  2. Place the PVC cap on one end and use duct tape to connect securely. 
  3. Put the tube into the laundry basket, with the open end facing up. 
  4. Trim the tube so it’s the same height as the basket.
  5. Insert PVC adaptor to the open-end and connect with duct tape
  6. Remove the tube from the basket, wrap the tube with the quilt or blanket, and secure it with duct tape. 
  7. Wrap the laundry basket with a blanket and use duct tape to attach it. 
  8. Put the tube back into the basket with the PVC adapter end facing up. 
  9. Add more batting with a quilt inside until there’s about a one-inch gap between the tube and the basket.
  10. Add activated carbon to the opening. 
  11. Cover the top of the basket with more quilt and cut out a hole to expose the PVC adapter. 
  12. Attach the ventilation hose to the PVC adapter. 
  13. Attach the other end of the hose to a fan/window/air ventilation location. 

Air should be able to flow through the carbon filter in and out if done successfully. The most important thing to remember is to secure each part. If there are holes or leaks, the filter won’t work correctly. 

 Carbon Filter for Indoor Tent

When do you have to change a carbon filter?

Now you have your carbon filter, and it’s been working for a while. Is there any maintenance that you’ll need to do? Yes, but not too much. 

Activated carbon is very porous and can absorb a lot of material, but it’ll become clogged and lose its ability to collect at a certain point. You can expect to change your filter every two years

If you smell marijuana outside your indoor garden, and it hasn’t been two years yet, you might need to check things out. Perhaps you need new charcoal; there might be a leak, a part could be broken, or something else. Luckily, our nose can detect if there’s any major problem with the carbon filter. 

On the flip side, if you’re having difficulties with diseases in your cannabis plants, this can also be from your carbon filter in your grow room not working correctly. 

For the most part, carbon air filters in your grow room are easy to make and maintain. You’ll have to work on it only if there’s a visible issue or it’s reached the two-year mark. Other than that, it just hangs out and does its job. 

Carbon filters final cleanse

If you’re an indoor grower and you don’t have a carbon filter, it’s time to buy or make one. Its primary function is to eliminate the pungent odor of marijuana from escaping the growing area. 

This will save you trouble with pesky neighbors, law officials, and guests from saying something about your cannabis harvest. Also, it can protect your vulnerable weed plants from deadly pathogens. Growing weed and smoking should be an enjoyable experience and leave you worry-free. 

So what’s the wait? Go to your local hardware store and get started on your carbon filter. If you’re new to growing, look online to buy cannabis seeds, so when you’re finished with the filter, you can get to planting weed right away.

About the author: Derek LaRose

Also known as The Cannabis Kronicles, Derek LaRose is a young ambitious cultivator and a staple educator for indoor cultivation.

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