I have two 4 inch passive filters (just holes) and I want to put a passive filter on them to help from geting dust and other small particles in my box. Not sure what I can use that wouldnt restrict air flow. I was thinking about using cut up panty hose or something. Anyone using anything?
I´ve been thinking similar thoughts. But I would not do it to protect plants from dust, was thinking of keeping the smell inside. But then I have understood if you have a good exhaustfan with carbon filter, then you wont need a filter in the passive intake. However, if you wanna protect plants, i´d say an old t-shirt (or any piece of cloth) might do the job of keeping the dust outside..
I have a pair of my mrs tights/ pantyhose over a 4" pot on my intake and it stops dust and pests, just vacume it every week to keep it clean. Ive been doing it for a few years and works fine for me.