Saltwater aquariums require a lot of time and effort to maintain, but they are also very rewarding.  Tangs are one of the most popular saltwater fish among aquarists, and for good reason.  They are colorful, active, and they are generally good fish.  They also come in an array of bright colors, which makes them a great choice for a family aquarium. 

A saltwater tang is an essential part of any saltwater aquarium.  They come in many sizes and colors, and they will bring energy and activity to your aquarium.  There are many species of saltwater tangs, all of which are beautiful.  Some of the most popular saltwater tangs are the yellow tang, blue tang, and flame angelfish.  These are all fish that are very easy to care for, and will bring tons of life to your aquarium.

Tangs are one of the most common saltwater aquarium fish. Among their many attractive traits, they are one of the larger fish. They also have a reputation for being quite personable. Although tangs are considered reef safe, they will eat small and slow moving fish. If you are considering a saltwater aquarium, tangs should be high on your list of fish to consider.

a Yellow Tang swimming in a reef tank
  • Average Length: 8 – 12 inches
  • Scale Colors: Blue, Black, Yellow, Brown and Purple
  • Attention Needs: Low
  • Good tolerance to Heat and Cold: Yes
  • Good Pet: Yes!
  • Good with Other Tangs: Depends on the species
  • Good with Other fish species: Only with non-aggressive species
  • Suitable for First-Time fish Owners: Yes
  • Health Concerns: They tend to have diseases like Marine Ich, Fin or Tail Rot and MHLLE.
  • Average Life Span: up to 25 years
an Achilles Tang with a beautiful spot

Physical Appearance of Tangs

Tangs are one of the most colorful saltwater fish species and it is one of the main reasons why they are kept in so many saltwater tanks. There are close to 80 different types of Tangs, each with a variety of different colors.  The most common colors include blue, black, yellow, brown and purple. 

Different types of Tangs can also differ in shape and size. Depending upon the type, Tangs can measure between 6 to 12 inches. 

A unique feature about their appearance is that Tangs have blade-like fins near their tails. They use it to fight with each other and also protect themselves from predators. This is why Tangs are often referred to as ‘surgeonfish.’ 

Yellow Tangs are a favorite and the most common for aquarium enthusiasts. They have an oval-shaped body and a long snout. They are a bright yellow color with sharp white spines on both sides of their tail. Yellow Tangs have 7 fins in total which includes the dorsal and anal fins.

An interesting thing about Yellow Tangs is that they change colors. During the day you can see that they are a bright yellow color, except on the spines. At night they change to a somewhat grayish-yellow color with a white lateral spine.

Powder Blue Tangs are another popular type. They have yellow and blue color tones on their body with a contrasting black coloration on the face. Just like the Yellow tangs, Powder Blue Tangs also have an oval-shaped body.

Achilles Tangs are also commonly kept by fish owners. They come in a dark brown or purple color with areas of bright orange and white around the fins and gills. An interesting part of their appearance is a bright orange tear-drop shaped pattern, near the caudal fin. In young Achilles the tear-drop marking tends to have a streak shape but can eventually change its shape when the fish grows.

Temperament of Tangs

Tangs are active fish who love to move around and explore their tank. You will find them moving at all the levels of the tank, especially the front and the center sections of the tank. 

They are generally solitary fish who like to live alone or in small schools of their own species. Tangs are peaceful and can thrive in a community fish tank. Some Tangs do tend to get territorial but if given a lot of space to move around, the Tangs will be happy among themselves. Giving them enough space will prevent them from acting aggressively with other fish. 

Some Tangs can also show aggressive behavior towards their own species. For example, Yellow tangs are known to get aggressive with other Yellow tangs. To defend themselves the Tangs generally use their bladed fins as a weapon.

Best Habitat for Tangs

When setting up a tank for Tangs, the most important thing is to give them a large tank. They may only grow up to 12 inches but need a large area to swim around. In their natural environment they are used to swimming miles in a day to explore. Having a large tank is important for them so they do not feel so confined living in an aquarium.

They can do well both in a reef only or a live rock only tank system, making them a hardy fish species. 

an Achilles Tang swimming in a reef tank

Tank size

Yellow Tangs need a minimum tank size of 55 gallons and for most other Tangs, a minimum tank size of 100 gallons is recommended. Anything smaller can cause them to feel stressed. 

a Powder Blue Tang swimming


The temperature should range between 72 to 82°F.

Water Hardness and pH

Tangs need slightly alkaline water so the pH should be between 8.1 to 8.4. The water hardness should be about 420 ppm. For reef tanks water hardness can range between 380 to 450 ppm. 


Tangs do not have any specific lighting requirements so any commonly found tank lightning will be fine. They will do well with a day and night cycle that many fish need. 


Tangs are known to actively feed on algae, so adding tank decorations like live rocks can benefit the fish. 

You can also add plants as they will act as a source of algae for the Tangs. Caves, driftwood and other similar decorations should be added to the tank as well. These will help to create several hiding places for your fish.

All the decorations should be placed in a way so they do not obstruct the movement of the Tangs. As mentioned before Tangs like to swim around so the more open space they have inside the tank, the better it will be for them.

Tank conditions

Before adding a Tang fish to a new tank make sure to properly cycle the tank. High ammonia and nitrate levels can be dangerous for Tangs like Achilles. They are extremely sensitive and adding them to a tank that is not properly cycled can result in their death. 

The salinity level of the water should be between 1.025 to 1.027.

Tank Maintenance

Measure the temperature, pH, water hardness and the level of toxic compounds like ammonia and nitrates every day. Purchase a saltwater testing kit to measure the salinity level of the water.

Since Tangs are housed in large tanks that will generate a lot of bio-waste, a weekly water change of 10% should be performed. If you want to change the water less frequently, perform a 25% water change every other week. 

Community fish tanks will generate higher bio-waste so a higher water change might be needed. Remember to mix the new tap water with a salt solution one day prior and leave it overnight, before adding the new water to your tank.

Best Tank Mates for Tangs

Most types of Tangs are calm and will get along with other non-aggressive fish species. When creating a community fish tank, remember to get a large tank as Tangs will need a lot of space for themselves.

If you plan to add different types of Tangs, make sure they are of the same size and introduced to the tank together. Otherwise they can get aggressive with the other fish.

Ideal tank mates include:

a Powder Blue Tang getting a bite near the bottom of the tank
a yellow tang enjoying a swim in a reef tank

Health Issues

Tangs are sensitive and poor water quality or nutritional deficiencies can result in the fish developing health problems. They are susceptible to the following diseases:

MHLLE (Marine head and lateral line erosion)

As the name suggests the disease causes damage to the tissues on the head and lateral line of the fish. Sometimes it will also infect their dorsal fins. The cause of the disease can be several things, including nutritional deficiencies or poor water quality. 

There is still not any conclusive research on the causes and cure of the disease. The best way to prevent Tangs from getting this disease is to quarantine all new fish before adding them to your tank. If you find your Tangs showing signs of the disease take them to a vet immediately.

Marine Ich 

Marine Ich is a commonly found parasitic disease in saltwater fish species. The disease is highly contagious and can spread unrestricted to other fish in the tank. A fish suffering from Marine Ich (also called White Spot Disease) will have white spots all over its body.

Other symptoms include:

  • Cysts on fins, skin or gills
  • Labored breathing
  • Pale Skin
  • Excessive skin mucus (antibacterial enzymes that fish secrete)

The exact source of the disease is difficult to find but it generally happens when a new fish or equipment that was used in an infected tank is introduced to the tank. Stress or poor water conditions can also cause the disease.

It is important to treat the disease immediately as it can spread rapidly to others. Keeping the infected fish in a separate tank is recommended as it will prevent the disease from spreading to other fish in the community tank. Treatments include using a commercially available medication like Formalin or adding a copper solution to the tank. Consult your vet for the best treatment option.

Fin or Tail Rot

Fin or Tail Rot is a disease in which the fins or tails of the Tangs get damaged. The fins will develop an uneven texture or a milky coloring in the beginning and gradually look like they have been torn.

Possible reasons can be other fish biting your Tangs, poor water conditions or dietary deficiencies. Sometimes Fin Rot can also occur as a secondary symptom of another disease. 

The good thing is that Fin Rot is easy to identify and there are several treatments available for it. The most common treatment is to add an antibacterial solution to your fish tank. It will kill the bacteria that are causing the disease and does not have a side effect on your fish.

Drugs like Oxytetracycline, Malachite Green and Tetracycline can also be used to treat infected fish. It is recommended to treat them at the first sign of the disease because any delay can result in the fish losing their fins or even death.

a yellow tang swimming
fish flakes

Feeding Tangs 

In their natural environment Tangs mostly eat algae from coral and live rocks. In captivity they should be fed a combination of vegetables and meaty foods. 

Algae-based foods like pellets or flakes should comprise a major portion of their diet. If your tank has plants, rocks and driftwood, the Tangs will feed the algae that grows on them. 

Tangs can also be given Spirulina, Nori and blanched vegetables like spinach and peas. 

For meat-based foods you can give them chopped scallops, mysis or brine shrimp and bloodworms. They can be given both frozen or live food. Always thaw frozen food before feeding your Tangs.

Give them an amount that they can eat within a few minutes. Remove any uneaten food after a few hours as Tangs will not generally scavenge for leftover food.

Related Questions:

Are Tangs good for new fish tank owners?

Tangs are prone to developing several diseases. Maintaining specific water conditions is extremely crucial to keeping them healthy and allow them to live long. They also need a very large tank which requires frequent and larger water changes. 

Introducing them to an existing or a new tank is also a little tricky. All these requirements make it difficult for new tank owners to look after the tanks. It is recommended that fish keepers have some experience managing a saltwater tank before having Tangs as pets.

Is it possible to breed Tangs in captivity?

Many fish owners have tried to breed them in captivity but have failed. Because this fish is so active the Tangs need them to be housed in a large tank if you want them to  breed. A minimum tank size of 175 gallons will be needed. Anything smaller will prevent your Tangs from mating. 

Even if they did mate, the limited space will make it difficult for the younger fish to survive for long. These requirements make it difficult for a hobby fish owner to breed Tangs in a small captive tank setup.

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