Good and bad Negative pressure examples

Hello all. New here to growing and the forums. Golgi apparatus is my journal. I have done some research but cant find a definitive answer. How much negative pressure is to much and how much is just right?
Obviously if tent poles are creaking and bending and your solo cups are getting sucked into the exhaust that is to much.
I’ve searched for videos, examples and tutorials but have not found anything.
As my tent sits now it’s getting sucked in an couple inches and is not to the point I am afraid of damage or collapse. I have my T8 exhaust on1 and T6 intake on 4 or 5 normally.

If anyone has some photos they’d like to throw up or links to examples that would be a great help. I"ve spent hours looking for good examples.

I don’t think anyone is measuring their actual pressure…as long as you’re not sucking in the tent to the point it’s encroaching on your grow space, or obviously collapsing the tent, you’re good. If odor isn’t an issue, you can run positive pressure as well.


Sounds like you have the cpm adjusted to the level you feel is correct. I don’t think intake and exhaust CPM are a cookie cutter set up.

Each requires finesse.

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im basically running my fans right now so they click on at 74 RH. They do that about once every 3 minutes and run for about 20 seconds . That’s keeping things at 70-72f and 72-74rh. I also have a little 6 inch clip on in there running 24/7 keeping the air moving and the ladies dancing.