Take your time when acclimating cardinal fish to your tank water. Once introduced they may hide out for a day or two but should come out once food hits the water. Give them lots of security by providing hiding places (think live rock) and they may be out in the open more. Feeding the cardinal fish can be challenging when first introduced to your tank. They can be quite finicky and will probably not go after flakes or pellet foods. You may need to start with frozen or live fish food and then try to get them onto vitamin enriched flake foods. Aqua cultured specimens should be a little easier to feed. You may be able to keep multiples in the same tank if it is sufficiently large enough, 100 gallon or larger aquarium. If you cramp multiples into a smaller tank you will probably see aggression among them, especially once a pair has formed. Banggai cardinal fish seem to be fairly disease resistant but you still need to take proper pre-cautions and use a quarantine tank before introducing them into your main tank. Keeping them in quarantine can also give you a chance to get them eating without any competition from others. Some of the fish you will find in this categorie is: Banggai Cardinal, Flame Cardinal, Pajama Cardinal, and many more.