carbon filter size?

My room is going to be 41.58ft3.... I am thinking of gettin a 4inch inline carbon filter that is 9 7/8" long by 7" diameter.

Will this be enough to stop the smell from about 20 plants in there... my fan will be blowing 100 cfm.

oh and theres a 52mm carbon layer thickness

20 plants? You're kinda on the edge of it being effective. I would probably go the next size up. The size you're describing is what I have and I use it in a cabinet, maybe 4-6 plants.

thanks... i was thinin it might be a little small