Should I run my exhaust fan all the time?

Ok, here is my set up. I have a 4x4x7 tent, 1000w hps air cooled by a 6'' inline fan. I also have another 6'' inline fan pulling hot air from the top of the tent(exhaust). When the light turns off so do the two 6'' inline fans. I also have two acylating fans that run constantly.

My question is, Do I need to leave the 6'' exhaust fan running constantly to pull in fresh air or are the two 8'' acylating fans moving enough air?

runnin co2?

def, leave it on . unless you use co2.

you can fit a speed control and turn it down for lights off no prob's but leave it on.

growem green--------spike.

I run a simular setup & run a PC fan at the top to exhaust, it runs 24/7 while the lights fan runs w/ the light & the main extraction fan is tied to a thermostat. you need some fresh air at night but not alot so the pc fan works for me

Unless you're adding CO2 then running your fans is the way you replenish the CO2 for your plants.