Can a Shark Outgrow Its Tank?

One of the subjects that is most heavily debated in modern day society is the argument over whether animals should be kept in captivity or not. There are countless documentaries debating this subject, and the argument of captivity vs the wild is something that most people have an opinion on. 

But, no matter how you feel about this subject, the simple fact is that the majority of wild animals are kept in captivity somewhere in the world. This includes land mammals, and it includes sea creatures too.

Can a Shark Outgrowa Its Tank?

In fact, there are actually more sea creatures in captivity than you would expect – sharks included. 

In some areas of the world, people actually keep sharks as pets. This is actually a lot more common than you expect.

When you think of sharks, your mind probably immediately jumps to great white and basking sharks. But, there are actually lots of smaller species of shark out there too. It is these smaller breeds that are often kept as pets. 

However, if you are going to keep a shark as a pet, then it is important to ensure that you purchase the right size tank for them.

In this guide, we will be taking a look at lots of important information about shark tanks, and answering the question “can a shark outgrow its tank?”. So keep on reading to find out the answer! 

What Affects a Shark’s Growth?

There are lots of things that you need to research before you buy a pet shark. Not only do you need to ensure that it is legal to keep that species of shark as a pet in your State, but you also need to research how to look after a pet shark. Part of this research will include taking a look at what affects a shark’s growth. So, let’s take a look. 


One of the biggest influences on your shark’s growth will be their diet. After all, the saying “you are what you eat” doesn’t just apply to humans, but to animals too. So feeding your shark the right diet is vital. 

In the wild, sharks are grazers who swim through the ocean, having their own pick at the prey that shares the waters with them. In captivity, this isn’t possible – so it is up to you to ensure that your shark has a good diet.

Most food sold to hobbyist shark keepers is full of fillers, so if you want your shark to have a healthy diet, research what your specific species of shark would consume in the wild. 

Water Quality

Something else that hugely impacts your shark’s growth is water quality. Nitrates and pheromones can stunt the growth of your shark, and these will exist in water that isn’t good quality. 

To ensure that your shark has the best quality water possible, you will need to regularly change the water. Most recommendations suggest that you should change 25% of the water in your shark’s tank every month, however some experts suggest that this isn’t enough. It is best to do your own research and decide what is best for your pet shark.

You should also try to make the water in your shark’s tank as similar to the water in the wild as possible. Water chemistry has a huge influence on how sharks grow, so try to replicate your shark’s natural environment if you want them to grow healthily. 


Finally, it is important not to overlook the influence that genetics will have on your shark’s growth. Sharks of the same species will not grow at the same rate as each other simply because their genetics are different to one another.

When sharks are bred in captivity, this can also lead to smaller offspring as the fish have adapted to the size of their tank. 

Ultimately, genetics will have a rather large impact on the growth of your shark. However, as the last statement has stated, the size of the tank where breeding sharks are kept will influence the size of their offspring.

So, if you want your shark to grow to their full potential, you need to provide them with more than enough room. 

How Do Sharks Grow?

Sharks grow in the same way that all living creatures do. So, their growth depends on the nutrients that they get throughout their lifetime. When a shark is first created, it will survive on the nutrients in its egg sack.

From there, it will move onto small fish, and as it grows it will move onto bigger and better prey. 

As is the case with all living creatures, a shark’s ability to grow really does depend on the nutrients that it gets from its food. While other things will impact this, diet really is at the heart of allowing a shark to grow to its full potential. 

What is the Right Size for a Shark?

Now, this really does beg the question of what is the right size for a shark? Well, ultimately the answer to that question will depend on your species of shark.

As we have said, there are lots of different types of sharks out there, and while some of them are massive, some of them are also tiny.

So, it is best to research your specific species of shark to discover how big you should expect your shark to grow. 

However, to help you out, here are some average sizes for sharks that you may keep as a pet:

  • Rainbow Sharks – 6 inches. 
  • Roseline Torpedo Sharks – 6 inches.
  • Bala Sharks – 14 inches. 
  • Harlequin Sharks – 12 inches. 
  • Bamboo Shark – 41 inches. 
  • Wobbegong – 10 feet. 

How Big Should a Shark Grow?

Can a Shark Outgrowa Its Tank?

So, how big should a shark grow to? Well, as we have just said, this will ultimately depend on the species of shark that you have bought. There is an endless list of different shark species out there, and the size that they grow to will depend on the type of shark that you have purchased. 

Thankfully, you can usually find out how big you should expect your species of shark to grow to by doing some simple research on the internet.

However, it is best to do this research before you purchase a shark, in order to ensure that you are prepared for the size of that animal. 

How Big Should a Tank Be for a Shark?

If you purchase a shark when it is a baby, then it will usually be very small compared to its adult size. For example, Great White Sharks are usually around 5 feet in length when they are born, by adulthood they will usually measure around 20 feet. The same principle applies to smaller species of shark too. 

As sharks are often small when they are young, it can be very easy to assume that you can get away with purchasing a smaller tank for your pet shark.

However, you shouldn’t do this, as your shark will grow, and this will usually lead to you needing to purchase a bigger tank in the future. To avoid this, it is best to purchase a larger tank to begin with. 

If you plan on keeping a single shark, then you will first need to research how big you should expect it to be once it is fully grown. Once you have this information you can calculate how big a tank you need to purchase. 

Sharks require a lot of space. So, you should purchase a tank that is at least 3 times the size that the shark will be once it is fully grown. Additionally, the width of the tank should be at least 2 times the length of the shark.

This is vital as it ensures that your shark has enough room to move around and grow. 

If you plan on keeping more than one shark in the tank, then you will need to purchase an even bigger tank again.

Will a Shark Outgrow Its Tank?

So, now that we’ve covered all you need to know about keeping a shark in a tank, it is about time that we take a look at whether, or not, a shark will outgrow its tank. 

Well, it is difficult to give a definitive answer to that question, simply because it will depend on the species of shark that you are keeping.

But, one thing is certain, if you purchase a pet shark when it is an infant, and buy a tank that is measured to the infant size of that shark, your shark will outgrow its tank. 

Purchasing a smaller tank will not prevent your shark from growing, but it will cost you more money in the long run as you will need to purchase a larger tank for your shark. While growth can be stunted by a shark being kept in a tank that is too small, it will not stop your shark from growing as it transitions from infancy to adulthood.

But, by the same principle, if you purchase a tank that is measured to the estimated adult measurements for your species of shark, the chances are that your shark will not outgrow its tank.

That is why it is normally best to purchase a larger tank to begin with. The same principle applies to all species of shark, including larger breeds of shark that are kept in aquariums. 


In short, yes, a shark can outgrow its tank. However, this will usually only occur if you purchase a tank that is not suitable for the size that your shark will reach once it is an adult.

To avoid your pet shark outgrowing its tank, you should purchase a larger tank, ready for adulthood. 

Thank you for reading!

Mikayla Adams