just bring it in from the hole in the top and have your filter hanging from top of tent with fan attached either inside or outside with ducting going out of hole at top the bottom hole is incase you are bringing fresh air in with another fan
i had the same tent with a 425 cfm 6" windtunnel and it worked great. i was able to control the temps just with the exhaust fan. i have a thread with it if you want to check it out. i also have a thread on how to build an intake filter as well.