The Purple tang needs open water for swimming as well as suitable hiding spots in the aquarium. Acropolis coral skeletons are known to be appreciated. It is not advisable to house the larger and active species in an aquarium smaller than 100 gallons / 375 litres.
Juveniles are known to be peaceful and they will often stay peaceful as adults as well if they are allowed to grow up together with other fishes in a non-crowded aquarium. Ideally add the Purple tang as the last fish to the aquarium.
The Purple tang can use its “scalpel” (spine) to defend itself and to establish dominance, but it prefers to scare other fish and will seldom retort to real violence. You should however avoid keeping the Purple tang with members of its own species or genus, especially if the species look similar to the Purple tang, since there is a high risk of actually injury in such situations. Similarly looking fish from other genera in the family Acanthuridae can also be a problem, particularly if they occupy the same niche.
This fish is considered reef safe with caution. It may nibble on stony corals with large polyps, especially from the genera Trachyphyllia and Catalaphyllia. Keeping your fish well-fed and giving it access to food around the clock (e.g. a piece of nori secured by a clothes-pin) can reduce the risk of coral destruction.
The recommended water temperature is 72-78º F / 22-25.5º C, the pH-value should be 8.1-8.4 and the specific gravity 1.020-1.025. Powerful water movements are strongly recommended. The oxygen level must be high if you want your Purple tang to thrive.