Most growers put the carbon filter inside the grow tent.
It’s just easier that way.
But it’s not the only way.
You can put the carbon filter outside the grow tent and it will work just fine.
It’s not much more effort either.
There are a few good reasons to do this, but most of the time you’re better off with it inside.
We’ll discuss why you might want to have it outside and if you do, we’ll help you get it set up correctly. There are a few key things you need to be aware of.
- 1 Carbon Filter Outside Grow Tent: Good Idea?
- 1.1 Why Use A Carbon Filter At All?
- 1.2 Reasons To Place A Carbon Filter Outside A Grow Tent
- 1.3 How to Place a Carbon Filter Outside Your Grow Tent
- 2 Carbon Filter Outside Grow Tent: Final Thoughts
Carbon Filter Outside Grow Tent: Good Idea?
It is better to have your carbon filter inside the grow tent instead of outside.
However, there are some circumstances and situations where this is not possible. Placing it outside the tent is still beneficial, just not as effective as inside.
Why Use A Carbon Filter At All?
Carbon filters filter the air in the grow tent, similar to how they filter the water in fish tanks, or how carbon filters can be attached to face masks to allow you to breathe in a cloud of hazardous gas.
Air comes in and gets forced through the special filter where impurities and odors are removed. It then gets forced out the other side as clean air that does not smell.
Carbon filters are a safe way to keep the air clean and odor free.
Most people use carbon filters not because they want pristine air in the grow tent, but because the smell of cannabis plants can be overpowering, especially during the flowering stage.
You may enjoy the smell for a little while, but trust me, after an hour you will be sick of it. More importantly, you don’t want anyone else to be able to smell it.
Reasons To Place A Carbon Filter Outside A Grow Tent
As mentioned, it is generally better to have the carbon filter on the inside of the tent. But there are a few good reasons why you might be better off placing it outside in the grow room vs the grow tent.
You Prefer Using The Space For Other Things
Grow space is valuable inside any grow tent, even large ones. You may not want to waste good grow space with a large contraption like a filter.
Most growers prefer to use all the space inside the tent for plants and lights. Of course, there need to be fans and stuff, but overall, you want to dedicate as much space as possible for growing.
Your Tent Is Too Small
There are plenty of smaller growers or hobbyists that only have a small tent for growing. And carbon filters can be a bit bulky.
Some tents are built taller, meaning you have a bit more space inside the tent. This could be a good solution that would allow you to keep the filter in the tent, as long as you have the vertical space to fit a taller tent. If so, check out our review of Quictent grow tents for an example of a taller tent.
The Tent Structure May Not Support It
Some carbon filters, along with the housings and mounting hardware, can weigh up to 20 pounds. This is not heavy per se. You can lift it easily without hurting your back.
However, some tents have weak aluminum tent poles that are already hard to keep straight. Hanging a filter in addition to lights and a fan may simply not be plausible.
There may be other reasons to place it outside the tent, but those 3 are by far the most common. So, now that you know the reasons to place it outside, how do you actually go about doing so?
How to Place a Carbon Filter Outside Your Grow Tent
Here is everything you need to do and consider, if you plan on putting your carbon filter outside your grow tent.
Decide Where It Will Go
Find a good spot to set up the filter before you start doing anything. It should be some place that has a good, sturdy spot to mount the filter, and that has sufficient space around it.
Try to select a spot that is close to your vent hole, to avoid having to use excessive ducting. The more ducting you have, the more resistance to the airflow, which makes your fan work harder (and may result in you needing a more powerful fan, or an additional in-line fan.
Get The Filter Ready
Unbox everything and put the included pre-filter on the carbon filter. Secure it with the rubber bands or elastic loops that come with it. The pre-filter will help do some of the heavy lifting and keep the actual filter working for a longer period.
Prepare The Ducts
The fan being installed inside the tent has some good benefits, but having to connect ducts to it is not one of them. This is my least favorite part of setting up a grow tent.
Cut the ducts to the correct length to go from where you install the carbon filter to the inline fan on the inside of the tent.
Use a sharp box cutter to cut the plastic and a good set of snippers to cut the wire rings. Once you have the duct work ready it is time to connect the flanges.
Connect The Ducting To The Fan And Filter
Connect the duct to the output port of the fan (the tapered bit). Run the duct from the fan to the vent hole that is cut in the tent.
It is best if you can run the duct in a straight line from the fan to the vent hole to the filter, or at least make as few turns as possible to decrease resistance inside the duct.
Now connect the duct to the filter and then seal the seams with duct tape and clamps until you can not feel any air escaping.
If you prefer to put the fan and the carbon filter both outside, follow these instructions:
Prepare The Carbon Filter
Following the same steps as the previous situation, unbox the filter and set up the pre-filter.
Choose The Location
As before, pick a good spot for your filter where there is ample space around it, and a good place to mount it.
Place The Fan On The Top Of The Carbon Filter
The fan has a tapered spout that will fit in the filter, but the joint will need to be completely sealed so that no air can escape. Use some good duct tape and give it a few wraps on the seam where the fan meets the filter.
Prepare The Tent And Duct Work
Cut a hole in the tent that matches the outside diameter of your ducting. Once you have a good clean hole cut, measure and cut a length of ducting that will reach from the tent wall to the fan filter combo unit you have set up outside.
Finish By Sealing Seams
Run the duct from your fan filter combo unit to the tent hole. Once it is run and secured, make sure you seal all the seams with some good foil tape and duct clamps for the spots where the duct meets the fan, or if you placed a receptacle on your tent wall.
Carbon Filter Outside Grow Tent: Final Thoughts
As mentioned earlier, having your carbon filter inside would be ideal and much easier to set up. But if that is not an option, or if you prefer to have it outside, just remember the key is to make sure the joints and seams are all sealed, and the ductwork is as straight as possible.
As long as everything is sealed well and you’re not using too much ducting (and with as few turns as possible), having the filter outside instead of inside won’t pose a problem.