i just got this guy over the weekend. i have him in a NC24 with a helfrichi firefish. the firefish has been in the NC24 first. approx 3 weeks. At first it was showing that they would get along great. Yesterday proved otherwise, he(clown) started to chase and nip at the firefish. the firefish is bigger than the clown. any one have any ideas y he would be showing aggression?