Hi, I am setting up a small cupboard grow room and want some help with finding out the best way to keep the smell down on the cheap. I have looked at carbon filter but think this might be overkill as I will only be having between 3 and 4 plants at one time. My space is H:6ft W: 4ft D: 2ft. Can someone please give me some tips on how I can keep the smell to a minimum as I intend to flower my plants in this space and can't have the house constantly smelling of budds. THX.