They would work but you would most likely have some shadowing in the corners and would need multiples. I have 3 A80s over a IM20 23.62" L x 15" W x 13" H and it is the perfect amount of coverage. The A80's have 12"x 12" coverage. If you were to raise them up to get more coverage you most likely would lose PAR. I would recommend a A360WE or A360X for the cube tank.