I currently have two tanks running and the 90 gallon has basically aggressive fish (dogface, bicolor angel, picasso trigger, huge filefish, dragon wrasse) and I just hate the look of nothing but rock and sand. Is there anything I can put in there that they won't pick at and eat? I assumed an anemone would be safe since they sting but they harass that, too. I don't want artificial plants in there, anything live that might survive these bullies?