how much space you have and how much your light can cover
The 25 plants together cover an area of 5 X 5 .... The light pretty much covers that area but I will have to rotate my girls every once in a while ...

My only goal is to maximize yield and I read somewhere on this board that taller does not mean more yield cause the top of the plant absorbs all lumens leaving almost nothing for the bottom ???????

Please help.