first time buying a fan. cant make up my mind.

im looking to buy a fan for my 4Ft x 2ft x 6ft tent with a 400 watt. i was thinking of a active air or a dayton. looks like cheap hydro has good prices. also i have a 2ft x 2ft vegging room that stays in 85 to 88 with a 250 watt and i have 6in booster fan that doesent seem to work to well. so im really lookin for two fans. i know vegg tent just needs alittle more then a booster, but the flower room i think should have a 6in around 400cfm right? with speed control..thanks

It sounds like you could get away with a 4'' inline fan for the 4x2x6. My room is 4x5x6, and the 4'' was not enough for my 2x400W, I had to upgrade to 6''. So I guess the 6'' is a better idea, eventually you could upgrade to a bigger light without changing anything... and when I bought the 6'' they were almost the same price as the 4''.

if it was me i'd go with what you allready said a 6'' with speed controller that way you can adjust speed to your likeing if its a bit to powerfull

I awlays go bigger in case you want to expand in the future... If you get a speed controller DO NOT get one of those speedsters... they are electronic and create a HUMMM.... The speed controlller that works best is called a VARIAC.. you can find them on ebay... they slow you fan down and don't create the Humm noise...