Hey i have a 20g tank with one convict cichlid who is about 2-3 inches. I had 2 other convicts in there but one was killed and i had to separate the other they were a little smaller than the bigger one. i was just wondering if there are any other fish i could put in there with him that he wouldnt kill? is it because of his size or the tank being too small? I was thinking about maybe getting a firemouth or angelfish but i think the angelfish would be killed. Advice is appreciated.