I have a mixed 75 gallon aquarium, with a couple haps, about 6 mbuna, 1 jack dempsey, one fire mouth, one texas cichlid, a couple plecos, and a catfish. I just removed a dominant oscar, and the second in line Jag. Both were about 6". The tank was always peaceful, but since I removed the O and Jag there seems to be a fight for dominance in the tank. How long does it usually tanke for the dominant fish to prevail? BTW the mbuna are going in their own tank, as soon as I can get rid of the evil red devil that is temporarily in their new home.