Passive intake to exhaust ratio

Ive been thinking of changing my intake and was wondering what ratio is the norm, I keep seeing a 2:1 and 4:1.
Im running a 6"exhaust with one 10" intake. I thought about adding another 10" but didnt know if that would be an overkill or not.
What is your guys thoughts on this?

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I’ve always controlled input to output ratios with fan speed rather than fan size. Fan size has been dictated by tent size. A 4" for a 2x4, a 6" for anything under a 5x5, and an 8" for anything 5x5 and above. Input and output are the same size and the output is run at a slightly higher speed than the input (with the same size fan) to generate negative pressure in the tent when it is closed.


I RUN A 6 INCH Exhaust fan 4 x 4 space pulling out the top on Medium speed with 2 passive holes open at the bottom 24//7 . Plenty of air flow negative pressure never had a problem. Also two Small Circulating fans one on Each side of the tent. Just my thoughts good luck :v::+1:


@kellydans Are both of your intakes 6"?

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Im asking about a passive not active✌🏻

Yes, @Dave That would be correct two passive 6 inch holes Opposite sides of the tent. Also install a piece of 6 inch flex with a snake bend so you have no light leakage.

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