how should I do my carbon filter.

i got a few filters. my vegging plants are putting off quite a stink can I put a filter on the outside of my vent and screw it into the wall with the4 inch exhaust hole? how much will it reduce a 70 cfm fan which would not be a terrible hing since air is exhausted after 45 secs

I hung my filter at the top of my tent in the middle because heat rises and that's where the stinky air will go, it then is ducted to a 6" can fan that is inside my tent (to help with noise control) then is ducted out a window. This helps exhaust the hot and stinky air through the filter then right outside. I even dried my medicine in the tent and you still couldn't smell anything that was exhausting outside.

Yea you want carbon filter first then your fan then your hoods then put outside. That way if any air leaks through the holds you are pushing it out rather than sucking in stinky air.