I just purchased a Spider 2000 for a 4x4, tis supposed to be for a 4x2 but I stuck one of my old LED'z in there with it until I can purchase another one. I'm 6 plants deep and the plants are happy, happy!
https://www.rollitup.org/t/bam-just-like-that-grow-happy.1026285/post-15712212