They did fine with some mid sized c.a cichlids. It's conspecific aggression that you have to watch out for. The wolves actually left the cichlids completely alone and at times teh cichlids would pick at them. The exception would be pike cichlids - both the wolves and the more aggressive pikes tend to dislike anything cigar shaped, and they war constantly when kept together. Keeping some more active, somewhat aggressive cichlids with them would probably help curb their aggression as well. Nothing TOO aggressive that will kill the wolves (no guapotes/midas complex), but maybe fish like synspilum, kraussi, carpintis, gymnogeophaus/satanoperca sp. etc. etc. Larger schooling fish like silver dollars or tinfoil barbs work as well.