Our sub dominant fossie male colored up when a venustus went into spawn. The dominant male almost made a quick dispatch of him. For about two weeks it was touch and go wether they were going to kill each other or just destroy the tank.
That was some weeks ago, since then the sub dom grew from 9" and silver to twelve inches and just as colorful as the Big Guy. For the most part they play nice now since I removed all the girls from the mix. Gonna trade one of them in for a Tyrannochromis nigriventer pair.
Here are some haps that are current and some I had prior. The growth rates on my haps were different. In my 220 gallon the Champsochromis caeruleus were probably the fastest growing. Around 2-2.5 years to be about a foot long. The N. Venustus has a pretty fast growth rate similar to the champsochromis. He was about 8-9 inches. Phenochilus tanzania was probably the longest time. Over 3 years and is about 7 inches probably a couple more inches to go. The exochromis is also slower growing. 2 years and is only around 6". I do water changes of at least 50% once a week and feed every other day omega one pellets.