Medium-sized fish dominate the standard community aquarium. This category covers the exact care requirements for species ranging from Angelfish to medium Tetras and Barbs. You must understand behavioral dynamics before mixing species. We detail the aggressive fin-nipping tendencies of certain barbs and the territorial requirements of dwarf cichlids. We explain proper schooling numbers. Six is the absolute minimum for schooling species to feel secure. You will learn the specific water parameter preferences of different regional biotopes. We cover proper dietary variation to enhance coloration and immune response. Stop crowding incompatible fish into confined spaces. You are creating a stress-filled environment. We teach you how to structure the middle and top water columns properly. Read our guides. Research your specific species. Build a harmonious, correctly stocked aquarium based on science and observed behavior.