Had the same issue, work for myself but had a meeting with NZ Customs in the afternoon , in the morning I was in the grow room working away (9 x Cindy 99 going strong), at the meeting was the local policeman who I new personally as we grew up in the same street. he said after the meeting-You must have some fantastic plants growing because you smell of strong cannabis...... he suggested wearing paper overalls at all times in the rooms, he was saying this is how they catch alot of growers - (mainly young guys) .....He is not a cop any more hes in a wheel chair .. Also if in the 4 x 4 room I would use a 8-10 inch fan/filter turned down low (EC fans are better for this hooked up to Inkbirds )- I exhaust mine via a roof vent/exhaust with a blow back joiner to stop smells /breeze from blowing back in ( this is a must in my view)