Odor is always of concern, you dont want the wrong person sticking their nose where it doesn belong! I too am doing a basement grow in my house. My grow room is about the same size, maybe 250csf however just a tad bit bigger. I have a pleated 12x12x12 filter intake from the basement to the outside going to a 450cfm blower fan, ducted. My light hood is one 1000watt vented 8" on both sides with an inline centrifugal fan 800cfm, exhausting to the rest of the basement(my growroom is a plastic tent style). I currrently have 22 flowering beauties at four weeks, smell barely creeps into the basement, none whatsoever in the upstairs house. Its not bammer either this is quality stuff, ranging from White Widow to Blueberry x Cheese. The only odor control I am using is Ona Gel in small dishes around the room. It has a nice aroma and actually works really good when around the ventelation. My airflow is so efficient and high that the smell barely catches wind. Now if I had odor issues I would stick a 8" charcoal K&N style exhaust filter on my hood. Simple is better sometimes, get your ventelation dialed and make sure your room has a good seal.