Blue Acaras - Aequidens pulcher - are one of the first cichlids i owned, some 25 years ago. They are a relatively peaceful, central american that should be in a tank of at least 40gallons, preferably more. They get along with other semi-peaceful cichlids, such as severums, Firemouths, some of the geophagus species, etc. Would work with silver dollars as well, which, in a large tank, is a nice site. They are hardy and eat anything. Don't keep them with more aggressive species of cichlids. A very nice fish that colors up well - related to green terrors, and often confused with them when younger - make sure they really are blue acaras. Enjoy!