You could place four of these tubes in a 6x6 cluster. 4 tubes x 4 COB strings x 3 COBS = 48 COBS, @ 80W = 3840W in a 6x6 footprint. If the tubes were square, 3' x1 x 4 sides = 12' x 4 tubes = 48 square feet per 1 foot of height. Admittedly you would need larger tubes if you don't want fried plants. Haven't given it that much thought, but it is a project I will apply my mind to in future if the opportunity and resources allow for it.