i would think it would be fine, would make one hell of a canopy tho. tough for light penetration, like he said, it will be fine for the tops but you better not try to lst or top or anything like that. i have seen multiple rockwool grow tables just packed to the gills with rockwool right next to eachother, thats 4inch rockwool cubes. half is 2 2 halfs right next to eachother thats 4 inches... so i realy dont see how it wouldnt work. just dont grow them out to be monsters. the way i see it, you could either grow a few big plants in there, or keep a bunch of smaller ones in there and dont let them get 5 feet tall. i would flower after 25 days veging so they dont crowde eachother tooooo much. just make sure you have a fan blowing on them so you can get more fresh air to all of them.