I have a 4x4 tent and a 4x8 tent. The exhaust is tied together with a T-connection. I have an 8" fan that exhausts into the attic then it's reduced to a 6" line/fan/scrubber. But, before it connects to the 6" duct there is a T that has a 8" scrubber attached to it. There is a PDF diagram attached. 8" fan: 420 cfm 6" fan: 240 cfm 4x4 tent: 106 cubic ft 4x8 tent: 213 cubic ft. The 4x4 tent is fine, but am I going to get enough circulation in the 4x8 tent with this setup? Has anyone done anything similar to this? I don't have any plants in the 4x8 yet. I have mothers vegging in the 4x4 and I'm planning on beginning cloning within the next few weeks and I want to get this set up properly before I put any plants in there.