I just got a 55 gallon tank and i want to put more colorful cichlids in it. Right now I have 2 rainbow cichlids and 2 parrot fish and 2 silver dollars. what would be a good kind of fish to put in there. I also heard that if u have common fish that are bigger then the cichlids when u buy them the more aggressive fish wont bother them is that ture. Please help. I am looking to start putting fish in my new tank ok sunday or monday