Well you first need to figure fan cfm. In a 4x4x5 room you only need about 100 cfm. Add in a 600 watt light and then you need about 125, add a few extra for ducting and ect and you need about 150 CFM exhausting.
That filter has a 265 cfm min rating, not the best choice unless u run 300 cfm or more through it. Max rating is more important but you want to be closer to minimum.
I thought so too but it has no problem drawing air. It actually rips the velcro off the separation door between veg & flower rooms. Thats two 3x6x7 rooms with a 4" passive intake from outside. The intake enters the veg room and there is another passive intake in the top of the seperation wall between veg & flower. The filter is in the flower room and runs into an air cooled hood and out. You can feel the suction with your hand at all intakes.
word, i set my fan to a dimmee. I use a squirl cage and a flange and screw nin on in the garge and suck it out and filter it out the attic. one of the stanly yellow squirl fanns, they are cheep and keep a room cold
/\ look at the combos on the site he suggested and get the $120 more than enough says:
Effective treatment requires the exchange of air in the growing area in a period of 5 minutes. Compute your requirements by multiplying the width times the length times the height of your growing area to obtain the total cubic feet. Divide this number by 5 to determine the proper filter size needed.
I like this setup, run mine on med speed for a 600w and does very well. I too reduce to 4", but no issues there. Better a bit too much carbon than not enough!