Smell & Detection issues

Ok, I'm new to this so bear with me.

I'm planning a setup in my garage with bringing in fresh air from inside through a coat closet, venting the exhaust up through the attic. I'll make a Carbon Scrubber and make it as airtight as possible. What I do NOT want to happen is have my in-laws come over or a neighbor come around and be able to smell it. I want it to be as smell free as possible. What can I do to totally kill the smell and keep everything in the cabinet?

Also do you mainly get the smell during the flowering cycle or all the time?

I've done alot of research and know that I have about 3 months to finish the flowering cabinet before the plants will be ready as I just put them in water to germinate.

I'll start a log on here on the cabinet and making sure its stealth and quiet.

depending on the strain man... jack smells in it's veg, and reaks in it's flower... get a strain that's not too stinky.. a friend of mine grew sweet tooth which is known for not smelling too much...