55 gallon stocking options?

Jacks are a cichlid and they can be very aggressive towards other fish. Their tank mates need to be as aggressive as they are or they will be picked upon. The blood red parrot fish is a cross between a Jack and something else. They are very aggressive, and will kill smaller fish. Bala sharks are a hard fish to keep because they need their water to be almost perfect. If you plan on having cichlids then stay with cichlids that are just as aggressive as they are or can be.