I have a 4x4x6 grow tent- I am ready to flower- My girls got quite big, although I have a carbon filter i need to get some air in there- what is the best way to connect and I attach a 4 or 6 inch duct fan to blow air in through the top of the tent.
Duct fans are ineffective to pull air through a carbon scrubber. Do not waste your time. Believe me, I learned this the hard way after spending almost $70 on two 6" duct fans. Build this: http://forum.grasscity.com/do-yourself/598023-basic-diy-modifying-stanley-blower-cooling.html Its cheaper and infinitely better. EDIT* Just realized you said to blow air IN to your tent. Why would you want to do that? Any intake source should be passive. What are you using to exhaust the air from your tent?