Some of the links in this post are affiliate links. All opinions remain my own.
You may have heard of carbon filters when research the best grow tent set ups.
Maybe you saw the phrase while shopping, or mentioned in reviews or recommendations.
With the amount of information crammed into the descriptions of these, however, it can be overwhelming to understand what they are, why they’re important and what to look for.
This short guide hopes to alleviate some of the confusion and help a first-time grower find the right filter for them.
Quick Top 5 Carbon Filters for Weed:
What is an Air Filtration System?
Typically air filtration systems for grow rooms are made up of three major components:
- Air Extractor - Regulates overall climate
- Interior Fan - Acts as the wind would, breaking up stagnant air
- Intractor Fan - Brings in fresh air from another room, plus limits air pressure caused by the extractor
Now that you know what most air filtration systems consist of let's take a look at some of the best carbon filters for growing weed.
Why is a Carbon Filter Needed?
A grow tent is a great way to create a controlled environment for your plants to thrive in.
However, the enclosed space will produce a lot of heat, humidity, and strong scent.
Often growers underestimate the strength of the smell their plants can put off, and end up buying a filter in a panic.
Going into a filter purchase uninformed, however, can result in lower lifespans for your fans and filter, and a higher likelihood that the filter won’t work at all.
Carbon filters are the preferred choice for most grow tent users.
They’re used across many industries for air purification, and provide effective scent removal at an affordable price.
Because they’re so effective, there’s a large range of filters to choose from, which can often be overwhelming for a first-time buyer.
Doing a bit of reading and research beforehand can save you time, money, and future headaches.
How Does Your Grow Tent’s Setup Affect What You Need?
A more expensive filter will usually weigh more; while this means an increased lifespan for the filter, it’s important to consider your grow tent’s location.
As exhaust fans are usually near the top of your grow tent, make sure that either your tent will be able to support the carbon filter you choose, or you have a way to install a hanging carbon filter.
Some professionals, such as those from General Hydrophonics, go so far as to recommend setting up your carbon filter before you install anything else, including grow lights and settling in your plants.
Don't forget to check out our guide on the best LED grow lights.
Be sure to know your exhaust fan’s CFM (cubic feet per minute) rate as well, since you want your filter to have a higher rating.
You need a filter that has a 20%-30% higher rate to ensure good exhaust at any given time.
A fan with a high CFM rate paired with a carbon filter with a low CFM rate can seriously damage or even burn your fan.
Even with these considerations, however, there tends to be a wide variety of sizes and shapes available to suit your needs and best fit your grow tent.
Just be sure to avoid using an in-line exhaust fan like the kind you’d find in your bathroom.
These fans usually aren’t powerful enough to work with a carbon filter, which means it will have a short lifespan.
If you get a fan too strong for your tent, you'll need to reintroduce CO2 back into the atmosphere. Luckily for you, we have a guide on THCoverdose.com to help you shop for one.
How to Find the Best Carbon Filter
Be sure to plan ahead and come prepared when shopping for a carbon filter.
Too often, new growers underestimate the need for a filter, and then rush for the easiest-to-find and cheapest filter.
You’ve already learned about the importance of buying a carbon filter whose CFM is higher than your exhaust fan’s.
It’s also important to consider the quality of the charcoal you’ll be getting in your filter.
Budget out how much you’re willing to spend on a filter:
The higher the cost, the better filter you’ll probably get.
A better filter will also weigh more, as the amount of activated carbon in the filter directly impacts how much odor it will absorb and how long it will work.
Generally, you want to go with the largest filter your grow tent will allow.
This will give the carbon more opportunity to absorb odors from the air.
So long as you choose the right filter to fit your grow tent, you can expect a carbon filter to last at least a year.
And potentially more, depending on the quality and amount of activated carbon in your filter, and the volume of air that moves through it.
Basics for Installing a Carbon Filter
It’s important to consider the way air is flowing when installing a carbon filter.
If installing a carbon filter inside the grow tent, the exhaust fan is pulling air through the filter rather than pushing air through it, which means the filter needs to be in front of the intake of the exhaust fan.
Black Dog LED, suggests that some growers have great success putting their carbon filter outside of their exhaust fan, however.
No matter where you put it, the carbon filter should have a pre-filter in front of it to keep mold, dust and any other particles out of the carbon filter.
It’s also possible to route your grow tent’s exhaust back into your grow tent, instead of letting it vent outside.
If you want to do this, you can connect your exhaust and intake fans, and install your carbon filter on the intake fan instead, either inside or outside.
By doing this, your carbon filter will be able to continuously clean your grow tent's air.
Before installing for the first time, be sure to vacuum your new filter to remove carbon particles.
While it can be a lot to consider, ensuring your carbon filter is installed correctly will help maximize the life of your carbon filter and your fans, as well as maximizing its odor filtration capabilities.
The Best Carbon Filter for a Grow Tent
The iPower 4 Inch 190 CFM with 4” carbon filter is a lightweight combination of both fan and filter.
The fan itself is made to be low-vibration and quiet, and the included 8 feet of ducting means you have many options for installation.
Included in the kit is everything you need to install the filter either inside or outside your grow-tent, suspended or resting on the floor with the connecting duct.
Plus, the filter comes with a two-year life expectancy, and includes a pre-filter which only needs to be changed every six months.
The filter has a 1050+ IAV (Iodine Adsorption Value).
People seem to love the filter and fan, citing few to no problems.
One of the only issues is an occasional problem with the fan itself, and how loud it can be when not on its maximum speed.
The Amagabeli 4 Inch carbon filter is an activated charcoal filter that has a 1050+ IAV rating and weighs about 7.5 pounds.
Made to fit any 4 inch duct or fan, it boasts 190 CFM, and comes with a washable pre-filter.
The Amagabeli is designed to be reversible, as well, which means it can be easily adjusted to fit either an intake or an outtake fan.
Some people do think that the flange is a bit too small.
Most, however, are able to adjust to the size difference easily.
For a simple and straightforward activated charcoal air filter, the Amagabeli has set itself up as an easy to maintain, solidly built and reliable choice.
The Growsun Air Carbon Filter is a 4 inch by 10 inch filter.
It includes a prefilter, but little information can be found on its CFM.
At 5.5 pounds, this filter is a comparably lightweight option.
It does its job well, and any issues encountered will be met by a great customer service team, a must for a first-time user.
The Vivosun 4 inch air carbon filter is a 1050+ IAV rated, reversible air filter with an included velcro prefilter.
Weighing in at 7.3 pounds, this filter boasts a two year maximum lifespan; the manufacturer recommends reversing the filter to help increase the lifespan, and replacing it after one year for maximum effectiveness.
The flanges on the filter are able to be swapped easily to allow for it to be installed as either an intake filter or an exhaust filter.
People keep coming back to the Vivosun because it's reliable, works and is backed by a great customer service team.
The iPower 6 inch air power filter is 16 inches in length.
It comes with a washable prefilter and a reversible flange for installation as either an intake or an exhaust filter, as well as helping increase the lifespan to two years.
Made with 1050+ IAV charcoal and weighing in at 11 pounds, this filter makes up for its larger size with increased effectiveness.
The flange is a little smaller than you'd think.
However, this does not seem to have much of an impact on most growers.
If you're looking to hide the dank odor that's permeating through the walls of your house, look no further than the Cool Grows 4 Inch Air Carbon Filter.
This air filter is perfect for not just masking scents, but flat out eliminating them.
Whether it's your grow room, kitchen or bathroom, the Cool Grows is an effective odor eliminator.
What’s also great about this Cool Grows product is that it is built to last.
In fact, once the carbon has run its course, you can easily unhook the fasteners, and refill with fresh carbon.
However, it should be quite a while before you need to refill because the flange on top is reversible.
Being reversible gives the filter a second life because it switches up all the unused carbon sitting at the bottom with the used carbon dwelling near the top.
This gives your filter new life and provides the air in your grow room new life as well.
There isn't much that sets the Cool Grows apart from the Amagabeli.
The most significant difference is perhaps the open areas of stainless steel mesh allotted for air flow.
While the Cool Grows has a total of 53% open area, the Amagabeli’s open area covers 55%.
This gives the Amagabeli product a slight edge in not only creating fresher air but eliminating weed odor as well.
Secondly, this amount of open space also makes it easier for the Amagabeli filter to cool down the immense heat that is created by the many lights hovering over the plants in your grow room.
Lastly, this filter can also be used as both an intake filter and exhaust filter.
Switching up the uses will also prolong the life of the activated charcoal living inside of your filter.
While the Grow Bright Double Layer technically does the trick, it does come with its share of hiccups.
Okay, who are we kidding?
It comes with a full set of road bumps.
The most glaring of these issues is how loosely the charcoal filter rests on top of the netting.
After all, the purpose is to bring fresh air in, filter out the bad air, and stop any contaminants from getting into your grow room.
However, due to the poor execution of the ill-fitting filter, some bugs can get past the outer screen.
Also, since the filter doesn’t sit snuggly within the netting, it can also be sucked into your intractor fan, depending on the fan’s strength.
While the dual layer design is effective in keeping most contaminants (besides bugs) out, the doubling up on layers does slightly restrict air flow.
Lastly, you may use Grow Bright Double Layer in screening contaminants from getting into your grow room, it not the greatest at masking foul odors.
Therefore, using the Grow Bright should still remove the musty scent that comes along with growing your herb.
This is perfect for a grow box (like the ones we reviewed in this buying guide) that has a filter that isn't carbon filtered already built in.
Regarding functionality and design, the Growneer is a lot like the Cool Grows and Amagabeli.
What sets this particular carbon air filter apart from the rest is that it comes with a removable pre-filter that you can wash and reuse.
The activated charcoal that comes with the Growneer can last upwards to a whole year.
Like many others, the flange and the bottom are both reversible.
While the Growneer's carbon filter lasts up to a year, the Vivosun's reversible features boast that the filter should be good for around two years.
This particular filter has a 53% open air flow.
That means the Vivosun is marginally not as effective as some of the others on this list in terms of deleting odors.
One nice perk of this filter is that it comes with Velcro straps intended to hold the filter in place.
Perhaps that is something that the Grow Bright Double Layer can learn from Vivosun.
The pre-filters that come with the Vivosun can be moved inside the mechanism to turn the tool into an exhaust filter easily.
While you can remove and clean the pre-filter, it is made out of foam.
This type of material tends to hold onto particles.
Therefore, you can clean the pre-filter with soap and water, but it might not be very effective.
Instead, you may be better off purchasing a brand new filter.
If you're going to starting a grow room you NEED an air filtration system.
It not only makes for healthier plants, but it also keeps your house from stinking like cannabis throughout your entire grow!
There isn't much too them, but the best carbon filter for a grow room is going to:
- Be able to handle the amount of air you need to push through it.
- Eliminate weed odor
If you don't want your neighbors finding out about your marijuana grow op, then you NEED to invest in a carbon filter.
This is one piece of equipment you don't want to skimp on either.
You can get the top of the line, for a fair price.
Just make sure to get a carbon filter that will fit your setup and large enough to handle the smell of your plants.
Do you use a carbon filter with your grows?
We'd love to hear any tips you have on them in the comments below.
We also reviewed grow tent air conditioners, you should check them out here.
Last update on 2021-03-25 / Affiliate links / Images from Amazon Product Advertising API