I have 15 sibling Kenyi cichlids that are around 2 inches in a 55 gallon tank along with a single Johanni. I like the fish and all is fine so far but I'm wondering if this is going to be a problem. The males have recently started turning yellow and it looks like at least 8 or 9 (maybe even more) of them are male. So far no obvious aggression but I've already had 1 tank full of cichlids go battle royal on me and I'd rather avoid that happening again.