Tents sucking in

I have an 8" in line fan sucking out my two 5x5x6'7" tents ran inline to each other and they are caving in alot one actually broke the corner plastic any tips would be awesome

Open some vents. Your intake Is too small for your outtake aka too much air exiting the tent and not enough going in at a fast enough rate. Try having intake 2-3x bigger then the outtake hole so if your outtake hole Is 6 inches use a minimum of 12inch intake hope this makes sense

I will try it thanks

Also to get a 12 inch intake u can open 2 x 6 inch vents if u have them spare or open your door zipper till the air isn't pushing The side of your tent in as much but try opening the spare vent's if you have them

There are also way to lightproof these vents if you are needing dark cycles.