EXACTLY what do I need

im going to buy this

http://cgi.ebay.com/Hydroponics-Ten...in_0?hash=item4ce8e58650&_trksid=p3286.c0.m14

I want to know EXACTLY which fan I should use

I found this 1...

http://cgi.ebay.com/6-Valuline-Cent...in_0?hash=item5ad019200f&_trksid=p3286.c0.m14


I guess im just a lil confused.. is it 6 inches around on both sides of the fan???


Also I dont want to spend more then 120$ on a fan... So if anyone could please link me to a fan that will keep the temps inside that exact tent under 80 would be awsome...


also with that tent.. do I NEED a fan blowing cool air in.. or will the exhaust fan be enough to pull air in from the flaps at the bottom?

The fan is 6" across on both sides

Not enough info. How big is your light? Is it air cooled? Carbon filter attached? How cool is the intake air?