So a few questions i have here i have read that LxWxH/5 is the way to find out my cfm. Is the 5 the minutes it takes for the air to fully circulate a room? When i plugged my grow room measurements into that formula i end up with this. Math- [LxWxH]/5 [6.5x3x8/5 =31.2Cfm Does that math look correct? Is 5 a good amount of time to circulate a room or should i go with like 2-3minutes? Thanks for the advice guys my plan is coming along great with the help of all you great growers! Edit: Do inline fans run air in and out(Newb to this stuff)?