Well here is my :twocents:

Just spend the extra $$$$ the fist time round to get a kick ass fan/w speed controller and no worries who cares.

And it will add some stress ya fan with the reducers how much all depends on number things. I was told awhile back but don't remember the cfm count tho. I would say just add 30-40 more cfm if you plan on using 1 reducer Imo.

But get a good fan and controller is the way to go. You can always adjust your fan speed and upgrade your lighting while not having to worry about it later. And ventilation is a key thing Imo with growing, It will either make your grow or break it, you decide.

Why would you wanna use reducers anyway, As this will reduce airflow.

Lets say your fan can more 60 cubic feet/min air moving with a 6in line, but you only allow 40 cubic feet/min to move as the 4in line is 1/3 the size smaller than the 6 so the fan is only moving 2/3 of the air the fan is capable of moving.... Makes sense, Sorry if it don't in :S5: the middle of my cigar.

Only thing that makes sense to reduce is a line off you Ac hood which would be stupid.

~One~:rastasmoke:
~budG~:rastasmoke::rastasmoke: