Carbon Filter


Hey Grobo Team,

I’ve noticed that the smell of my plant becoming very strong over the past week. Any chance I can make an adjustment on my end to help with the smell?

Anyone else having similar experiences?



Hi Richard,
meaning you can smell your plant outside the grobo?



Correct, previously i would noticed the smell after I had checked on the plant, but now as soon as I walk into the room where it’s located the entire room is beginning to have a strong smell. It’s leading me to believe that it may not be working properly.


That sounds bad. For me that would be a real issue. Hopefully just a rare failure and not a common problem.


Hey Rich,

Is your temporary air pump cord preventing you from closing the door completely? This will cancel out the carbon filters design.



Hi Stephen,

So I can confirm the door is shutting completely. I would like to note that today the smell was not nearly as strong so maybe yesterday I may not have had the door shut which could have been what took place. Either way, I will keep an eye on the door and smell!

I appreciate the feedback!


@Stephen @Rich this made me think of a question will we have the ability to add more carbon filters into the Grobo? I know there are products like the smoke buddy which lets you blow smoke into it but essentially it’s just a carbon filter so I didn’t know if we could stick more in grobo if that would help at all lessen the odors


If your growing Basil or herbs, would it be ok to take out the carbon filter as those smells are not all that bad and intrusive? Would this do any damage to the plant/grow cycle?


HI @feesh4life, That’s fine to remove the carbon filter for smells you’re comfortable with. It won’t affect the plant in any manner.
Do keep the filter housing in place though, don’t want to accidentally damage the fan or your fingers if anyone reached up inside.


Thank You Jason.


Update: I can confirm that the smell is definitely leaking out of the unit now that I’ve had the weekend to keep an eye on it. The door has been shut properly and locked at all times with the cord from my third party air pump. Smell hits you as soon as you reach our guest bedroom door.

@OGJ are there any immediate changes I can make on my end to help mask and or eliminate the smell. Would using the second filter in the additional nutrient box be useful? The smell is becoming very powerful and I’ll definitely need to find a solution ASAP as I live in an apartment. Let me know what we can do!



Check this out @Rich Gel Fresh Linen - 1 Gallon Pail Ona
This work well for me sucking up strong odors


Great advice Jamminbear! I’ve used it in the past and it works well. Not sure you need a gallon pail though. :wink:




I too am having very strong smells leaking from unit. I have two ona gels on top of the unit and it does not seem to be helping. Not sure if the smell is from the exhaust or leaking from around the door. Does anyone know of anything like air purifier fans etc that work?


What kind of strain are you running @Blackthumb? Two ona gels not helping is strange, maybe try to position them differently in the room? I know people have success using this air spray.



Just piggybacking on this thread to chime in about smell.

Since I’m right near the end of my grow the smell has been increasingly undeniable.
We have the grobo in a well ventilated room (garage) with an oscillating fan going as well, but regardless, these last couple weeks have been hit-you-in-the-face potent even before you get to the room.
Not quite the stealth I was originally looking for.
A little disappointment on my end.

I’ve ordered an ona get to see if it will help. I wonder, if in the test labs because they are bigger rooms, the smell never seemed that big of an issue?


I am growing original amnesia from dinafem
I have positioned 2 separate ona gels in various positions with no luck. I just picked up and air cleaner with multiple carbon and hepa filters. Running it now and will see in the am how it is and will report back


What air filter units did you get?..I also purchase one myself but got a really good deal on a oransi HEPA