Lights out smell which direction does the smell go

420r · Feb 15, 2025

Lights out smell is the fresh-cut-grass smell that happens at night when your grow lights turn off.

It is not the same as weed smell but its like a hay, or wet or freshly cut grass smell.

More info here: https://www.420magazine.com/community/threads/lights-out-smell.495766/

My guestion is, what direction does this smell go to? Because I thought smell usually goes up, but since my downstair roommates reported the smell but my upstairs did not im kinda puzzled. Obviously I dont wanna bother people.

Thanks

Galgrows · Feb 15, 2025

Sorry i can't give you the answer your seeking. Is this a apartment building or a home with multi levels? My whole single story house smells like that but i live alone. My family an friends know i grow so they are used to it when they visit.

Coconutz · Feb 15, 2025

Without an extraction fan running the smell falls straight out of the tent after the light goes off, I've small b/w plastic squares on the inside of my ducting acting like back draft shutters preventing the smell falling out of the tent into the room.

They also stop stray draughts getting waffted out inadvertently from oscillating fans.

420r · Feb 17, 2025

Galgrows said:
Sorry i can't give you the answer your seeking. Is this a apartment building or a home with multi levels? My whole single story house smells like that but i live alone. My family an friends know i grow so they are used to it when they visit.

apartment

420r · Feb 17, 2025

Coconutz said:
Without an extraction fan running the smell falls straight out of the tent after the light goes off, I've small b/w plastic squares on the inside of my ducting acting like back draft shutters preventing the smell falling out of the tent into the room.

They also stop stray draughts getting waffted out inadvertently from oscillating fans.

yeah i use fans for extraction which are on 24/7 also filter but the bottom of my diy tent is open to suck in fresh air

HerbalEdu · Feb 17, 2025

you need a powerfull enough extractor with a good quality carbon filter (they are not all necessarely as efficient depending brand or if DIY) running 24/24, so that the extractor create enough negative pressure in your box/tent/cupboard to prevent any odor leak

420r · Feb 17, 2025

HerbalEdu said:
you need a powerfull enough extractor with a good quality carbon filter (they are not all necessarely as efficient depending brand or if DIY) running 24/24, so that the extractor create enough negative pressure in your box/tent/cupboard to prevent any odor leak

Yes but lights out smell is something different than regular cannabis smell, the filters do not work for this.

See:
- https://www.420magazine.com/community/threads/lights-out-smell.495766/
- https://www.icmag.com/threads/plants-smell-stronger-when-lights-go-out-whaaaat.289923/
- https://www.420magazine.com/community/threads/smell-as-soon-as-lights-and-fans-go-off.144325/

So I dont mean the regular cannabis smell you can smell during the day, im talking about the wet-grass or hay smell you get as soon as the lights turn off. This is very different

amneziaHaze · Feb 17, 2025

420r said:
Lights out smell is the fresh-cut-grass smell that happens at night when your grow lights turn off.

It is not the same as weed smell but its like a hay, or wet or freshly cut grass smell.

More info here: https://www.420magazine.com/community/threads/lights-out-smell.495766/

My guestion is, what direction does this smell go to? Because I thought smell usually goes up, but since my downstair roommates reported the smell but my upstairs did not im kinda puzzled. Obviously I dont wanna bother people.

Thanks

Smell goes where the air goes.if you have hot air it goes up if you have cold air it goes down. Basic fisics

HerbalEdu · Feb 17, 2025

no it isn't different, it's normal for the smell to vary across the grow.
there's nothing like "light out" smell where carbon filter doesn't work search for scientific sources next time not urban legends on whatever forum post .

here's an article that explain the basic:

Do cannabis plant odors vary from day to day? | Grow Weed Easy

by Nebula Haze Do plant odors vary from day to day, say a real lot some and practically none the next? YES, that is totally normal. It is normal for cannabis plants to smell, and for the smelliness to change from day to day. Cannabis plant odors may change a lot from day to day....

www.growweedeasy.com

if it smell outside the box that just mean your system isn't sealed enough and/or without enough negative pressure and/or with a cheap carbon filter that isn't efficient enough

HerbalEdu · Feb 17, 2025

420r said:
Yes but lights out smell is something different than regular cannabis smell, the filters do not work for this.

no, no, and no,... the amount of bullshittery since i started to help you few post ago is sometime killing me ¯\_(ツ)_/¯

then explain why most of us don't have any smell coming out of the tent when light off if the smell was so different ... ... ...

amneziaHaze · Feb 17, 2025

I wanted to say with carbon filter nobody came to my house and said that it smells like anyplant.maybe yours is old

Coconutz · Feb 17, 2025

420r said:
yeah i use fans for extraction which are on 24/7 also filter but the bottom of my diy tent is open to suck in fresh air

It sounds like your filter needs replacing that shouldn't happen with a fan/filter running.

Lights out smell which direction does the smell go

Lights out smell which direction does the smell go

420r

Galgrows

Coconutz

420r

420r

HerbalEdu

420r

amneziaHaze

HerbalEdu

Do cannabis plant odors vary from day to day? | Grow Weed Easy

HerbalEdu

amneziaHaze

Coconutz

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