Exhaust fan and carbon filter

A question from a fellow grower:

Hey how are you a question do I have to exhaust my grow tent and of so what are good cheap exhaust fan and carbon filter for a 2x4x6 tent

http://www.amazon.com/gp/product/B004Q2ER5C/?tag=greenrel-20

I have the 6 inch one for my 3x3x7 and found it quite large but a great performer.

Perfect , and add a 6 inch duct fan and you would be in good shape.

Hi guys! I also have a question about ventilation. I just built a new grow room and as of right now I have no ventilation in it, I just keep the door open most of the time for airflow. I plan on running intake and exhaust fans, ducting, carbon filter, etc. My question was, what are some ways I can light proof my intake air hole? For right now I just wanted to cut a hole and put a small fan in front of it but how can I do that without light getting in or out?

You can buy a fan with a damper and it will close when the fan is off. The blades when it’s on will block most of the light. You could also fashion a black pre-filter on the outside of the fan. Ducting usually does a good job, at least that’s what I noticed with mine.