YASoob ,
hey been a min. sorry for slow reply .
i started w/ only 1-1000w. n expanded later . thus the 2- 6in. vortex fans verses the 1-8in. / as far as your filter , 6in. vortex will be fine .

i have a couple sharp turns in my duct work . i have no light leaks w/ galvanized ductwork and it doesn't obstruct flow like the accordian foil type duct.

also doco is right , plan 1= bad cause you'll be pulling carbon dust through your lights n gettin em all dirty .

i'd go w/ the 8in. on lights -n- 6 in. on filter .
my rooms not to loud w/ 3 blowers going , but i have a fan speed controller on the 2-6in. blowers -n- my stuffs in my basement anyways .
peace
crispi :thumbsup:
xcrispi Reviewed by xcrispi on . CFM backpressure i was reading this on another thread fans are tested without ducting which give them the cfm. The thread also mention that if you use ducting, it will cut the cfm by half. No one on that thread asked if it will cut more than half if ducting and carbon filter is use. It got me thinking since i just upgraded and i need a fan that will cool 2000watt in a 64 cubic feet room. Any input on this would be great. thanks in advance Rating: 5