IMO tank needs some flowing motion. Euphyllia glabrescens, torch coral would be nice. Clowns may even take to it. Also some different color, maybe a nice neon green Caulastrea echinulata candy cane. Or maybe some Favites sp. red and green moon coral. Also some photosynthetic gorgonia. Pteregorgia, Plexaurella etc. These will be brown so will add a different color and some motion.