cooltube question

will a computer fan be enough to cool the cool tube if not will two computer fans be enough? what do you think/say/experienced??

Sorry....you'll need one of those inline fans from a DIY store. Like a 250cfm

How big is your grow room and light?

my grow room is 0.8x1x2m and i have a 400hps! i already have such a fan my current set up is the the air is pulled from the ceiling of the cab through ducting through the cool tube through the fan and then it gets out through the carbon filter. my air exchange in the room is about twice a minute! but this way i have to run my fan 20/4 the 4 when lights are off otherwise tempts get too high!! so i was wondering if i could use some computerfans i have left over to cool the tube and then place a thermostat for the inline fan so it goes on only when needed!! this way i can use co2 more efficiently!!