I've settled on two for now but still not sure if it's right?
Any advice would be much appreciated.
![thanks :thanks:](./images/smilies/double-thumbs-up-thanks-smiley-emoticon.gif)
Thanks mate, two open seems better than one at the moment as one on its own causes too much of a kind of wind vortex and was stressing the smaller plants. With two though it seems fairly stable. Thanks mate!2-Scoops wrote: ↑Wed Oct 06, 2021 1:16 pm1 or 2 should be fine, i run a passive inlet myself in my grow cupboard. I've always gone by x1.5 to x2 times size passive inlet hole to your extraction fan, but i see your running oversized gear. But yes i would think 2 is more than enough in a smallish grow tent.
Negative pressure isn't all it's cracked up to be - it makes no difference to the plants and is really just about making sure that the smell doesn't esacpe before passing through the fan and filter.