Have you noticed your saltwater community fish becoming timid and spending most of their time hiding? This is not uncommon in peaceful saltwater community aquariums that contain large amounts of live rock.
In the wild, most community fish are constantly on the lookout for potential predators. Though these instincts remain with the fish even in captivity, to be constantly nervous and on "guard" is not normal behavior. In the protected confines of an aquarium, it may be an indication that the distribution of fish species is not in balance.
An effective way to encourage shy fish to come out in the open is to incorporate a small school of dither fish that remain in the open. By acting as watchdogs, a small school of dither fish gives the rest of the fish in the aquarium a sense of security.
When choosing a school of dither fish for your aquarium, choose species that will naturally form a tight school. Fish such as the Blue/Green Reef Chromis or one of the many peaceful
Cardinalfish, are great choices. In aquariums large enough to accommodate several different schools of varying species, Cardinalfish of different species will join to form a single large school, creating a dramatic effect in the aquarium.
Be sure to choose at least three of the same species to avoid any aggression. Also, make sure your aquarium is both large enough and has sufficient filtration to accommodate the newcomers.