DIY 6In inline fan help?

I have all the stuff set up for my grow room, its 3x3. Only thing i need to do is cool my cooltube. I only need enough fan power for a straight 3ft run, the air will be seperate from the growroom, just intake on one side, through the cooltube, and out the other side.. any thoughts on how i can build a cheap diy 6in fan? Im about broke... so the cheaper the better! Lol

how many pc fans can you get a hold of?

As many as i need im sure, lots of computer repaur stores around

do it right.

Get a high velocity inline centrifugal fan. Match the size to the hoods flange. If you have 6" flanges on the hood, get a 6" fan.

What are you doing for odor control? Air circulation?

I would use one fan for both and passive intakes.