Hi, I'm going to be buying a around a 55-60gal tank for my cichlids, I have a Hongi, Red Zebra, Kenyi, Ngara White Tail, and a yellow lab right now. They're all still about 2-3 inches. I've heard overstocking in a larger tank can curb agression. I'm wondering how many more fish I could add to the tank I'm going to buy. I'm contemplating adding in more yellow labs. Could anyone suggest more peaceful/not very agressive mbuna cichlids. I understand that I'd likely have to take out the kenyi and hongi. Thanks!