i take it you are just starting out... the thing about growing is... it gets easier as time goes on and you arm yourself with lots of information and good equipment. I know carbon filters and fans cost a lot... im using a crappy one for my veg room right now but pay the extra money - get a good one - it could be the difference between your neighbours tipping you off to the police or not. I have a plug in ozone generator as well for supplemental scrubbing... its just background ozone ie less than 100mg/hr and its safe to be around - just plugs into my wall, id reccomend one of those - you can get them very cheap off ebay and they do the trick.
The plants can stink so bad that you should really get a good quality carbon filter to solve all your woes - hope i helpled