Best kept one per tank unless the system is very large
Diet
Omnivore, marine-algae-heavy
Time
High
Cost
High
Overview
The Regal Blue Tang is a large, active reef fish that grows far bigger and lives far longer than most buyers expect.
Reaching up to 30cm, it is a fast, near-constant swimmer that quickly outgrows the small tanks it is often sold for.
This is an advanced fish.
It needs a large, mature reef system, stable water, and an experienced keeper prepared for a decades-long, expensive commitment.
It is frequently sold to beginners who lack the space and equipment it requires.
Housing
Provide an established reef aquarium of at least 1100L (290 gallons) with a long open swimming area and live rock with caves it can dart into when stressed.
It is reef-safe and benefits from strong flow and good oxygenation.
Keep parameters stable: temperature 24-27C (75-81F), salinity 1.024-1.026, pH 8.1-8.4, ammonia and nitrite at zero, and nitrate low.
A fully cycled, biologically mature tank is essential before introduction.
Diet
Tangs are grazers that need a diet rich in marine algae.
Clip dried nori or seaweed sheets in the tank daily and offer good-quality marine flakes or pellets plus frozen mysis or brine for protein.
Vegetable matter should form the bulk of the intake.
Frequent grazing supports digestion and reduces aggression.
A varied diet with added vitamins helps prevent head and lateral line erosion (HLLE), which is linked to poor nutrition and water quality in tangs.
Health
Blue tangs are prone to marine ich (Cryptocaryon) and velvet, partly because of their thin scaling and sensitivity to stress.
Quarantine every new fish and minimise stress during transport and acclimation.
They tolerate copper-based treatment well, which is a useful tool in a hospital tank.
Watch for white spots, scratching, rapid breathing, and faded colour.
Head and lateral line erosion points to poor diet or water quality.
Stable conditions and good nutrition are the best preventatives.
Temperament
Generally peaceful toward other species but territorial toward other tangs and its own kind, especially in cramped quarters.
A single specimen per tank is safest unless the system is very large and well aquascaped.
Newly added fish are often shy and may hide or wedge into rocks.
With time and space they become bold, active centrepiece fish that need room to roam.
A good fit for
Experienced reef keepers with large systems
Hobbyists wanting a long-term centrepiece fish
Keepers committed to quarantine protocols
Those with the budget for a large setup
Common mistakes to avoid
Sold small, but grows to 30cm and outgrows small tanks
Advanced
Beginner
Intermediate
Beginner
Beginner
Beginner