Discus really do better in a species tank environment..or with small calm tank mates. For example: You have a group of discus as the main inhabitants of the tank..you can also add a school of smaller fish like tetras, rainbows, rasboras...some cory cats, and algae eaters like otos, and SAEs. A few dwarf cichlids are fine tank mates, too. Discus should not be kept in 'general community' set-ups...and a low bio-load is very important to them.