African cichlids are well known among aquarists for their aggression and territorial behavior and hence, they can be difficult to care for when not handled properly. If you are going to keep them with other community fishes or cichlids, you need to pay extra attention to the issue of water requirement and compatibilities with other cichlid species.

Firstly, you will need to ensure that the fishes in your aquarium come from waters with similar pH level. African cichlid comes from three main African lakes: Lake Malawi, Lake Victoria and Lake Tanganyika. The general idea here is to not mix cichlids from different lakes as the pH level of the water are not the same.

The same logic goes with all the other fishes in you aquarium. Do your research beforehand and ensure that the fishes in your aquarium live in similar water condition before putting them together.

Secondly, after considering water compatibility, you will need to look at their temperament. One of the most complex and problematic issues surrounding cichlid is their behavior towards other cichlids. You will find that most cichlid display "selective aggression", meaning that they are only aggressive towards the same species or species that bears close resemblance to them.

The rationale here is that cichlids perceives similarity as a threat to their survival (compete for the same food, same partner, same territorial preference, etc). Thus, the general idea here is to not mix cichlids of similar color or shape as they are perceived as a threat.