I have friends who work in the oil patch piss once a year or so , 1 month for a light smoker will prob. pass but if you can reschedule for an extra week or so be on the safe side .
Sorry dude I have to disagree , Carbon filter work . But only if all air leaving your grow space is properly scrubbed , sure its going to stink like high heaven in the room . But the air leaving through the filter no smell ,smells like nothingness