Hippo Tang Tank Size – What’s The Best Option?

There are different types of tangs in the trade. However, hippo tangs seem to be quite popular among various aquarists. Although it is not a fish for a novice, experienced aquarists sometimes make mistakes when handling hippo tangs.

One of the commonest mistakes is choosing the appropriate tank size. The main reason is that hippo tangs grow steadily, from about 3 inches to 5 inches in the first two years. They generally add up to about 2 inches every other year. This is why many often use the wrong tank sizes.

Are you wondering what the best option is when choosing a tank for your hippo tang? Check out this article to find out.

Hippo Tang Profile

The Hippo tang is an Indo-pacific surgeonfish species that goes by several common names. These common names include Royal Blue Tang, Blue Hippo Tang, Blue Surgeonfish, Regal Tang, Pacific Regal Blue Tang, Flagtail Surgeonfish, and Palette Surgeonfish.

But it is the only member of the Parancathus genus, and it goes by the scientific name Paracanthurus hepatus.

This indo-pacific fish is endemic to the Indo-Pacific Ocean. It is common to see them in the Great Barrier Reef of Australia, the Philippines, Indonesia, Samoa, Sri Lanka, etc. It is pretty common in the aquarium hobby for its striking blue color.

They grow really big in the aquarium, up to a maximum length of about 12 inches. Although they grow pretty big in the wild, they prefer to stay in pairs. Alternatively, they love to live in groups of about 8 – 14 individuals.

Hippo tangs are very active swimmers and make sure to move around the tank a lot. A typical hippo tang will explore every inch of your tank in a very peaceful and playful manner. They sometimes dart in an instant and, at other times, swim graciously.

It would be best to use the recommended tank size to ensure that they have enough room for all that movement.

What is The Best Option for Hippo Tang Tank Size?

As mentioned earlier, Hippo tangs can grow as long as 12 inches and more in the tank. Hence, choosing the appropriate type for your fish is necessary.

Your tank must technically be no less than 150 gallons for a full-grown Hippo tang. But many experienced aquarists will put that number at 180 gallons. It would be best to keep the minimum at 180 gallons, especially if you plan to add some smaller fish for company.

Many newbies in the aquarium hobby often make the mistake of buying a small tank because of the small size of the fish. This would be a very expensive mistake because the fish will outgrow the tank, and you will be forced to get a bigger tank in the end.

So, it would be best to get at least a 150-gallon tank so that you can provide your fish with a comfortable environment.

Note: The 150-gallon tank size is the recommended tank size for Hippo tangs. But you may have to increase the size slightly if you want to keep more than one Hippo tang or if you want to have a community tank.

Why You Should Use the Recommended Tank Size for Your Hippo Tang

The main reasons you want to use the recommended tank size for Hippo tangs are the health and safety of your fish. Hippo fangs are quite interesting. They are active swimmers and require a lot of room for swimming and exploring the tank.

So if you do not want them to become susceptible to stress from living in a cramped space, it would be best to get a 150-gallon tank or something bigger for your Hippo tang.

Is There a Specific Tank Size for Quarantining Hippo Tangs?

The least tank size for Hippo tangs is 150 gallons. But during quarantine, what is the appropriate size for the quarantine tank?

Quarantining is very important to prevent the spread of diseases. If your fish is about 6 inches and below, you can use a long 20-gallon tank for quarantining. This is especially helpful if you just purchased the fish or are moving it from your friend’s aquarium to yours.

If your fish is longer than 6 inches, you may use a longer tank for quarantining. A 36 inches breeder tank is a good choice for this. It can house adult Hippo tangs and give enough space for movement as recovery takes place.

But if you have a much larger tank, either as a spare or empty, you can use it for quarantine purposes.

When Can I Use a Relatively Small Tank?

Although the smallest recommended tank size for Hippo Tangs is 150 gallons, there is one instance where you can keep a Hippo tang in a small tank but only temporarily.

You can use small tanks to keep your baby or juvenile Hippo tang as it grows to maturity. You can keep mid-size Hippo tangs in a 90-gallon tank, but that’s only as far as it goes.

A full-grown Hippo tang has to be kept in a 150-gallon tank or bigger.

What Can Go Wrong if I Use a Smaller Tank?

Sometimes, aquarists often report getting away with taking shortcuts instead of using the recommendations for optimal results. While you may get away with it when taking care of other species, the same may not be true with Hippo tangs.

The recommended tank size for Hippo tangs is so because anything less will result in the following:


Hippo-tang aggression is one of the commonest consequences of a small tank. In big community tanks, it is common to find that a Hippo tang is naturally a model citizen. They often swim around their favorite places and explore the tank.

You may even find it getting along well with your clownfish.

But in a small tank, you can be sure that your Hippo tang will harass any smaller fish in the tank. This is usually because the tank is not big enough. Since the tank is not big enough, your Hippo tang will generally not have enough room to swim freely.

The natural result is that the chances of confrontation with other smaller fish increase in a small tank, and this can be a problem for your smaller fish. Remember that Hippo tangs are not completely docile fish; they are semi-aggressive.

But they can become even more aggressive in a small tank if they keep bumping into other fish.

The only way to avoid this problem is to use the recommended tank size for Hippo tangs. You can also go a little bigger, especially if you are keeping a community tank. You want to add lots of decorations, live rocks, corals, hiding places, plants, and many other decorations.

The decoration will provide a hiding place for the smaller fish if they are confronted by your Hippo tang or any other threats. But more importantly, your Hippo tang will have enough room to swim, and the larger tank will reduce confrontation with tank mates.

Always remember that it is best to do it right to avoid irreparable damage to other fish in the tank. Remember that aggression in fish can often lead to severe injuries and stress, which would warrant a quarantine.

Using the right tank size is a sure way to prevent all that risk and extra work taking care of injured fish.


Many things cause stress in fish. These include improper temperature, overcrowding, wrong water parameters, and poor handling. However, using the wrong tank size can bring your fish under stress.

When you put a free-spirited fish like the Hippo tang in a small tank, you limit how much room it has for swimming around, which can lead to stress. While this may not be apparent in its younger years, as the fish begins to grow bigger than 5 inches, it will come under stress from the cramped space.

When this happens, you may notice symptoms like the development of unusual swimming patterns, crashing at the bottom of the tank, or other unusual behavior like darting across the tank. You do not want this for your Hippo tang. Using the appropriate tank size would ensure that your fish lives a happy and fulfilling life.

Bottom Line

Getting the right tank size is not negotiable, especially if you wish to keep the hippo tang until it reaches maturity.

You can do many other things apart from getting the right tank size if you want your hippo tang to live a fulfilling life. One of the first things on the list would be to use decorations, especially if you introduce them to your tank at a very young age.

You want to have live plants and lots of rocks. These decorations will be hiding places for your hippo tang to avoid being eaten by other bigger fish until it is mature enough to swim freely.

And when your hippo tang is mature, you want to reduce the decorations to make room for unrestricted movement in the tank.