The Yellow Tang is a lemon-yellow surgeonfish and one of the more recognisable marine fish.
Captive-bred stock now exists and is the more responsible choice.
Although hardy once settled, it is not a beginner fish: it needs a large tank, grows substantially, and is prone to disease when stressed.
It is an active, all-day swimmer that grazes algae constantly and can live for many years.
The name "surgeonfish" comes from a sharp scalpel-like spine at the tail base, which it can use defensively, so handle it with care during maintenance.
Housing
Provide a long tank of at least 280L (75 gal) and ideally larger; tank length matters more than volume for this fast swimmer.
Keep salinity 1.024-1.026, temperature 24-27°C (75-80°F), pH 8.1-8.4, and nitrate low, with strong flow and good oxygenation.
Give plenty of rockwork for grazing and refuge.
Add it last to an established tank, since territorial tangs claim space, and quarantine all new fish to keep marine ich out of the system.
Diet
The Yellow Tang is primarily a herbivore.
Its diet must be algae-based: offer dried marine algae (nori) clipped in the tank daily, plus algae pellets and herbivore frozen foods.
Grazing on natural algae growth supplements this.
A diet too high in meaty foods causes poor health and dull colour, so keep it green.
Frequent small feedings suit its constant grazing.
Vitamin-enriched algae sheets help maintain colour and support the immune system.
Health
Yellow Tangs are notably susceptible to marine ich (Cryptocaryon) and to head-and-lateral-line erosion (HLLE), which is linked to stress, poor water quality, and inadequate diet.
Strict quarantine of all new arrivals is essential to keep ich out.
Maintain clean water, strong oxygenation, and an algae-rich diet to help prevent HLLE.
Watch for white spots, scratching, faded colour, or pitting along the head and lateral line.
Good husbandry lets this fish live for many years.
Temperament
Active and generally peaceful toward unrelated fish, the Yellow Tang is territorial toward other tangs and similar-shaped fish.
It is reef-safe and helps control nuisance algae among corals.
Keep only one tang per tank unless the system is very large with several added together.
Its tail spine can injure tankmates and careless hands, so respect it during maintenance.
Given space, it is a bold, ever-moving centrepiece.
A good fit for
Intermediate keepers with a large tank
Reef tanks needing natural algae control
Long-term committed aquarists
Ethical buyers choosing captive-bred
Common mistakes to avoid
Tanks too small for its swimming needs
Skipping quarantine - prone to marine ich
Insufficient algae/veg in the diet
Housing multiple tangs that fight
Is your enclosure big enough?
Minimum volume280 litres (74 US gallons)
CompanyMust be housed alone. Best kept singly; territorial with tangs
In a reef, stability matters more than any single target number. A parameter moving fast does more damage than a parameter sitting slightly off.
Go now
Any detectable ammonia or nitriteWater change now with matched, mixed and aerated saltwater. Stop feeding. Directly toxic, and a marine system has less margin than a freshwater one.
Now
Temperature or salinity has moved sharplyCorrect slowly, over hours, not minutes. Check the heater and the top-off. The speed of the change does the damage. Correcting fast repeats the injury in the other direction.
Now
Rapid gilling, or a fish hanging in the flow breathing hardIncrease aeration and check temperature and salinity. Warm water holds less oxygen, and a heater failure shows up here first.
Now
Today
White spots, or a fine dusting like icing sugarIdentify which parasite before treating. Most reef tanks cannot be treated in place. The two common parasites look similar and need different handling; velvet can kill a tank in days.
Today
Corals closed for more than a day, or receding tissueTest alkalinity first, and compare it against the last reading rather than a target. Unstable alkalinity is the most commonly cited coral killer, and a swing shows up in the trend, never in a single point.
Today
A new fish added without quarantine now looks unwellRemove it to a separate system today if you can. Nearly every wipeout in a reef tank traces back to a skipped quarantine.
Today
Quarantine every new animal, including corals and inverts. It is the single practice that separates a reef that lasts from a reef that restarts.
This is general guidance for a healthy adult, not a diagnosis. An exotics vet who knows your animal always overrides it — and the time to find one is before you need one.
What it really costs
Setup, monthly, first year and across a whole life, itemised and with the electricity worked out from the actual wattage. Published figures for the same animal disagree by a factor of four, so the calculator shows ranges rather than picking one.
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