African Cichlid Compatibility

African cichlids are tropical freshwater fish found in the sediment-filled waters of African lakes such as Tanganyika, Malawi and Victoria. They are a popular aquarium fish because of their fascinating characteristics and bright coloration. However, African cichlids are very aggressive in nature, and are not considered community fish. They are known to kill other types of fish, and often pick on other cichlids. Aquarium hobbyists who keep cichlids must plan their cichlid aquariums carefully to avoid aggressive behavior.

  1. Tank and School Size to Reduce Aggressive Behavior

    • When selecting African cichlids for an aquarium, the size of the tank is very important. Larger tanks give cichlids plenty of space, which allows them to set territorial boundaries. In addition, larger schools of cichlids exhibit less aggressive behavior. One male per cichlid variety along with four or more females will generally make the cichlids more passive and social as they swim in schools.

    Environmental Factors and Cichlid Aggression

    • Paying attention to water temperature, mineral and pH balance, and aquarium substrate will also keep aggressive tendencies to a minimum. African cichlids require water temperatures around 73 and 82 Fahrenheit, a pH balance of 7.8 and 8.6 and sand or gravel substrate that mimics their natural habitat. The aggressive nature of this fish is also decreased by providing plenty of hiding places in the tank. Large rocks, driftwood and decorative items with nooks and crevices work best. Because cichlids are active and like to move lightweight items, heavier tank decor items will stay in place better than small shells and artificial plants.

    Compatibility with Other Fish

    • The extreme aggressive tendencies of African species make it very difficult to put other types of freshwater fish in their tank. In a matter of days, passive community fish such as goldfish, guppies and barbs placed in a tank with cichlids will be injured, killed and devoured. However, in a large tank that has been carefully planned with a proper balance of cichlids, some schooling freshwater fish might be accepted by the cichlids. Aquarium catfish, sharks, loaches and large tetras in groups will sometimes be ignored by cichlids. However, because cichlids require an environment with hard water and sediment, these freshwater varieties will often fail to thrive in a cichlid environment. The cichlids might also target the less-aggressive fish by nipping or picking at their fins and bodies.

    Compatibility with Other Cichlids

    • As a general rule, cichlids do best with other cichlids. However, they sometimes act aggressively to their own kind, so certain factors must be taken into consideration when planning a tank full of cichlid varieties. One male per group of females decreases aggressive behavior, because many males will become territorial over the females. Selecting cichlids of similar size is recommended, because larger varieties have the tendency to pick on smaller cichlids. In addition, keeping cichlid species that vary in appearance will decrease the likelihood of aggressiveness. This is because similar-looking cichlids may become territorial. Color, shape and species variations will keep a more harmonious balance in a cichlid aquarium.