Intake and exhaust Questions

[Cosmic Charlie]

I am looking to add an intake to my room and I see all these filters at the hydro store that basically look like car filters except they are like $100 ... My question is I have family in the car business and I can get that stuff cheap... Whats the difference ? is there even a difference between the expensive hydro filters and a car intake air filter? I am also wondering if I have a 6' inline fan from hydro farm ... What size intake will I need ? Is there some sort of rule of thumb when it comes to that? Thanks in advance!

 

[namvet25]

http://www.amazon.com/Hydroponics-Inline-Scrubber-Carbon-Filter/dp/B004Q2ER5C%3FSubscriptionId%3D06KMPSHEDSXXQMQVT482%26tag%3Daskcom0http://www.amazon.com/Hydroponics-Inline-Scrubber-Carbon-Filter/dp/B004Q2ER5C%3FSubscriptionId%3D06KMPSHEDSXXQMQVT482%26tag%3Daskcom05-20%26linkCode%3Dxm2%26camp%3D2025%26creative%3D165953%26creativeASIN%3DB004Q2ER5C5-20%26linkCode%3Dxm2%26camp%3D2025%26creative%3D165953%26creativeASIN%3DB004Q2ER5C

 

[Duck Commander]

ahhh mate i dont know about using a car exhaust as a filtter? the carbon in them is a special one from Australia (rhino filter) and is specifically to stop the smell of herb:group:

 

[Cosmic Charlie]

No not the exhaust . The air filter on a car and I am wanting to use it to filter the air I am blowing into the room from my intake. Not the air I am sucking out from my exhaust I already have a carbon filter for the smell on my exhaust... I just want to make sure the air going in is clean and cool...