with fresh air intake tooClean air does so much .It brings good things in and bad things out.
I like clean air every day!
My main reason for a fan circulating in a tent is to build up stems.
BUT ffs! now that I think of if, with the few plants I grow at a time as opposed to 40 and 36 plants I came from.
Hard to do what you want to 40plants.
With that said I defoliate ,lolipop.low stress train .