Not all Lake Malawi cichlids make suitable tankmates. Peacocks should not be housed with Mbuna or other boisterous cichlids such as Labeotropheus, Petrotilapia, Metriaclima, or Pseudotropheus species. While it is true that Mbuna and Peacocks both live in the rocky biotopes of Lake Malawi, they infrequently have contact. Peacocks typically reside at a depth of 6 to 40 m; Mbuna on the other hand, are usually found in the upper 5 m of the water column (Spreinat 1995). The reason for this difference is due to dietary differences between the two groups. Mbuna graze the algae growing on the rocks in the lake. The algae require strong light in order to flourish. Peacocks live at depths far too deep for the algae to grow in abundance. It follows therefore that Peacocks and Mbuna are not natural conjoiners.
Mbuna and Peacocks make poor tankmates primarily because Mbuna have a considerably more aggressive temperament (some would even say obnoxious). Their aggressiveness and hyperactivity have a tendency to stress the Peacocks. Keeping Mbuna together with Peacocks usually proves deleterious to the latter who are kept in a constant state of subordination. Some hobbyists who mix these two fish may argue that no such unfavorable conditions exist. This may sometimes appear superficially to be true, but Peacocks kept with Mbuna do not grow as fast, are less colorful, and do not live nearly as long. Peacocks removed from such an environment show dramatic turnaround within a short period of time, confirming the sensibility of this recommendation.