Help With Exhaust Fan Strength

The volume of my grow room is 100 cubic feet. I recently purchased an Elicent 8" inline fan. It's rated at 670 CFM. Is this too strong for my grow room?

I also have an Elicent 6" inline fan, which is rated at 309 CFM. I figured this was probably too weak for my grow room.

Which should I use? Noise is not an issue.

using a fan that is too big and turning it down using a controller is best