Well im going to petsmart in about 12-13 hours and i need to know if a firemouth is compatible with a........?

Question

tiger oscar it size?..if not a firemouth then what fish? and the tiger oscar and cichlid will be the same size

Answer 1

Regardless of what size you buy them, they might not grow at the same rate.  Oscars grow rapidly and are known to eat just about anything they can fit into their mouths.  Consider this before purchasing anything to go with your oscar.