You should figure out your fan needs in a more scientific way. The basic calculation is:

Room H x L x W / 5 (minutes) = Initial CFM

Then add:

+ 1.3x for filter

+ 1.3x for muffler

+1.5x for any elbow in duct

+10% for each foot of duct

I'm guessing that a 170 CFM fan will be more than sufficient for your tent. This will also reduce your the size of the filter you need so examine that was well.