this is my grow room, 4x8x12 space, black plastic curtain folds up, 3 simple thumb tacks holds it open. when down, I enter from the end. plants include 4 white rhino clones, 1 master kush sprout, 4 blue dream crossed with master kush, 1 adolescent white rhino that I'm pretty sure is male, and 1 adult female white rhino 4 weeks into flower. I simply remove the flowering white rhino from the room for darkness. Just haven't taken the time to separate the veg/flower section yet.
Get some poly film that is white on one side and black on the other from any grow store or amazon. Put the white side in towards the plants. It will increase the light in the "tent" by 25% or more compared to black on the walls. 3m industrial velcro in 2" wide strips is the coolest shit ever for something like this. I use it on my 4x8 tent to keep it split into two 4x4 rooms.