Do I need an active intake?

[illGatess]

Doing my first grow. Do I need an active intake or is passive intake hole fine? If so how big should it be? Growing in a 4’x8’x80” 6-12 plants 2 oscillating fans inside the tent. How much co2 does every cannabis plant need? My exhaust fan takes out 402 CFM at full power (which I probably won’t have it at) and is being ducted to outside. The room I’m growing in is an average bedroom. Can I just do a passive intake from the bedroom it’s growing in? Will this be enough fresh air for the plants?

 

[bboyfromwayback]

A intake with your setup wouldn’t be needed

 

[Smallgrow]

Im not expert but I have a 3x3 x80” tent when 2 plants flowering. I opened a second passive intake vent flap it made a huge difference. Maybe experiment with that, I have a modest exhaust fan at 4” . They say 4 times the size of out put for intake but I think more is better my humidity is running 10% lower now than before.

 

[changeofpace2014]

i added a computer case fan (after some research on cfm). Note: I had to build a air passage tunnel / maze which stopped any light coming. Flat black paint and corrugated black material was used on the walls especially when the direction changed. Worked out really well.