do I need a ventilation system for one plant will it help keep the smell down I’m growing in a closet with grow tent 3 x 3 x 72 five gallon buckets dwc
It depends. If you live somewhere where the extremely pungent odor of marijuana isn’t going to draw undue attention to yourself, then you’ll be fine.
I use this in my 3x3 tent
exhaust fan and filter
https://www.amazon.com/Powermaxx-Premium-Charcoal-Carbon-Controller/dp/B010IVOWO0/ref=sr_1_6?tag=greenrel-20
just filter
https://www.amazon.com/gp/product/B008NYF8S4/ref=oh_aui_search_detailpage?tag=greenrel-20
I use that fan and the second filter with great results. If you are going to stay in a 3x3 tent then just get the 4 inch models
Also different strains have different bouquets. Some are very strong while growing esp in flower. I once almost bought a strain on another site till i found out while in flower it smells like cat urine. My tents in my bedroom so it was a definite no! Your exhaust fan will help pull out heat as well as smells.