Your set up is fine. Your using your vent kinda like duel purpose for the lights and the room, I get it, How is your humidity in the tent? The more humid your room the less effective your filter will be. Carbon can only do so much in the best of cases, humidity clogs pores and air passes right by. If you really want to get rid of the smell a inline ozonator is the 100% cure for it. Yoy could get rid of the carbon filter all together and increase your cfm's.
Their costly but well worth it IMO.