I have 2 tanks. The ferocious ones in the bottom tank. The not so ferocious ones in the top tank. I use plants, drift wood and rocks to distract them. The dominant fish tend to take the best places. The rest just take the other hiding places. The plants provide some additional vitamins & minerals. Top it up with frequent maintenance of the side filters and external filters. Not to mention the cleaning of the glass. No excessive feeding. Besides, I may need your help to dispose off some once they get too big for the tanks.