For my first grow , I was writing things down and asking google all kinds of questions. Like how to measure sq feet lol. All I know is how to measure , but there's allot of free calculators for sq feet online. And there's a lumens guide in this forum somewhere. I did allot of research and this is my 2nd grow I just followed the basic outline of my last grow. The only difference now is I'm using a closet instead of a armoire. The lumens are off a little but I calculated for max lumens anyways so I'm still in the healthy range.