There will always be fin nipping. I actually have 5 of each of the three(Regular, Albino, and Green) you can have. The more you have the less they will fight because they won't be able to focus on each other. Atleast 4-6 I would say. 6 especially since you have them with cichlids. I have them in my 125g with my F2 Male Midas and no probs. Just remember with cichlids that can change at any moment. I just am lucky to have a fat, lazy, and chill Midas.