Many African cichlids come from the Rift Lakes which are cool in some areas with hard water. South American cichlids are in mostly warm very soft water. Central American cichlids live in cooler water than SA's and the water is a little harder but not as hard as those from the Rift Lakes. Then people always confuse West African cichlids with those of SA because the also are in warm soft water BUT putting them together in the same tank may cause problems due to the fact that their 'fright' patterns are different. Some patterns are striped vertically and others are horizontal and the fish may not recognize which is which.Yes! I depends where each fish comes from originally! They may exist in each others conditions but won't be happy and may not be able to re-produce.