plz help me get my carbon filter in workin ... advise needed:D

plz can any1 help me out i know how to set up my carbon filter but when lights are out and i close my tent the carbon extracter will be pullin the air out of the tent well if i leave my fan blowin over my plants will this be ok? or would cuttin a hole at the bottom of my grow tent enable me to have the carbon filter on durin lights out? i could put a hole at the bottom of the tent thats more of less touchin the wall would that be ok?,,im only goin to have the carbon filter/extrator on when lights off if my grow turns out really stinky .. otherwise it will only be on during lights on if needed and the tent is allways open a bit durin lights on .. sorry if ive worded this all wrong.. i just want to make sure i get things workin right plz any1 advise needed thank u...

The way I did it, was make a hole in the bottom of the growing room with some sort of lighttrap so that no light can enter or exit via that hole. As I understand, constant refreshing of the air in the growroom, is best for your plants, even with the lights of. Thinking about that, I read somewhere on this forum that most growth takes place during dark hours but keep in mind that I'm a beginner ;)