Ventilation for 4x4 grow tent

Hi all,

I'm planning a grow in a 4x4 grow tent and I have a question about the proper ventilation needed.

The setup involves a 600W MH/HPS with a light hood, that I'm gonna cool with a 6'' fan with dedicated ducting (so it goes intake > fan > light hood > exit). That fan is rated at about 110 cfm, so I'm thinking it should suffice.

Now for the grow tent ventilation itself I wanna use a carbon filter and another 6'' fan rated at 165 cfm with passive intake (plus a rotating clip fan inside the tent). So my question is quite obvious now - is that enough ventilation for that space, given that I'm already using a different fan&path just to cool off the lights?

I figure the easy answer would be "no", since at that rate the fan would clear the air a bit faster than once per minute (theoretically), and then there's the carbon filter factor (no additional ducting & turns though, it goes straight out). But do I really need more then that, considering the lights are already being cooled off separately? From a purely (or almost) CO2 replenish point of view, could that 165 cfm fan do the job or is a bigger one a must?

Thanks a bunch!

I have a 4by4 by 7 tent with a 600 watt hps for flowering,I originally had a small coffee can looking in line fan that was the same diameter as the 6in duct it wasn't strong enough to push the air up threw a wood stove vent stack.When the light was on the temperature was 15 to 20 higher than the room temperature, bigger inline fans that are more than twice the vent diameter move plenty of air to circulate and cool my tent,i think it is 750 CFM. I'M just a ham an egg er that gets 12 to 14 OZs per run,so other more skilled growers might have a better way of venting and controlling your growing environment