I suggest you build one your self.

Calculate the volume of your grow room, and have your fan try and exchange that every 5 minutes.
That's a rule of thumb... not exact science.

Anyways, you can get activated carbon at the pet shop... probably cheaper if you search around.

Build your self a box...
Put some window screens' material at the bottom...
Make a layer of activated carbon.

Attach fan to top side... pull air through the bottom.

That's the basic primer.

Helps?
turtle420 Reviewed by turtle420 on . Carbon Filter / can fan So I've used the DIY odor eliminator, and used Polar blabla Ona, and Fresh linen. The odor is still there, must be some strong strain, though....it's only bagseed. So I'm wondering from where, and what exact can fan/carbon filter I should get. My tent is approximately 10' X 8' X 8', and the veg room/drying area surrounds it. I'm wanting to do all I can to eliminate odor as the outside is heating up, and odor will become a little more apparent. Rating: 5