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How Big Will A Shark Grow In A Fish Tank?

Sharks are lovely fish to have in a personal aquarium. Chances are, you are considering one of these independent fish for your current community. 

Perhaps you are wondering if it will outgrow your fish tank. Factors such as the size of the fish tank, diet, and its environment are often the main culprits in shark growth. 

When considering a shark addition to your tank, it is best to choose your shark before hitting your local pet store. Read on to find how a big shark will grow in a fish tank.

Can a shark outgrow its tank?

Can a shark outgrow its tank?

Tank rules are that a fish will grow as big as the tank. However, this is not true for sharks. 

Sharks are quite the opposite. The average shark size is 6 – 48 inches, and you can either have a full-sized personal aquarium shark or an undersized one. 

Over-sized sharks are not common in a fish tank. Personal aquarium sharks do not reach their full potential size. 

If you feel your shark is a little too big, check on your shark species. It may be a bigger shark from the beginning. 

If this is the case, you will need to upgrade your tank size to accommodate your shark’s size and its activity. 

Fish tank vs. open water

Sharks in personal aquariums are not really sharks, as you would think of their saltwater versions. They are from a species of freshwater catfish or carp called Cyprinidae. 

Cyprides’ are not huge fish and do well in tanks but originate from large rivers. Naturally, living in a tank will strain its growth. 

Sharks living in fish tanks do not have the same conditions as their natural wild aquatic habitats. 

They are introduced to pet stores and new personal aquariums in similar sizes but change to varied sizes over time, depending on the kind of shark. 

Most sharks begin exceedingly small; some, however, grow to a significant size. This can be bigger than the average 55-gallon tank can comfort. 

Types of sharks for your tank size.

When considering shark sizes, you can check an adult shark size chart. 

Below are common sharks sold in pet stores and their common adult sizes. This will help you immensely when finding how big a shark will grow in a fish tank.

Common Shark NameAvg Max Shark Sizes
Rainbow Shark (most common)6 inches 
Rosaline Torpedo Shark6 inches
Black Red-Tailed Shark6 inches
Harlequin Shark6 inches
Silver Apollo Shark7 – 9 inches
Bala Shark10 – 13 inches
Violet Blushing Shark12 inches
Black Shark Minnow24- 36 inches (fast growth)
Chinese High-Finned Banded Shark30- 40 inches 
Iridescent Shark36-48 inches

How does the tank environment affect your shark’s growth?

A community of fish in your aquarium may become a factor of size if your shark senses over-crowding. Too many fish can become a huge issue in a shark’s growth. 

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Other fish will cause your shark to believe the tank to be smaller than it is. You could find your shark reacting in abnormal behaviors when new fish are added to the aquarium. 

Sharks who sense over-crowding may become territorial. They will often chase other fish. A shark who is consistently chasing for space may be stressed. Stress will slow your shark’s growth.

A shark that cannot grow to its full size will eventually die. 

Adjustments to the environment 

Your shark will require extra oxygen to maintain its size. Lack of oxygen will affect how fast and big your shark grows in a fish tank. 

To help your shark’s oxygen levels, include an air pump in your tank and monitor the changes in your shark’s growth.

If you have other fish in your tank, you may find that your tank is more temporal for other fish and less admirable to your shark. 

While this may not directly affect the size of your shark, you must be willing to compromise on environmental conditions and give your shark some time to adjust to the changes. 

How does diet affect a shark’s growth? 

How does diet affect a shark’s growth? 

Sharks are fed often; nonetheless, their diet does not directly determine their adult sizes. A shark’s diet is utilized for health. 

Many dissimilar sharks require different diets; a robust diet leads to a robust-sized shark. 

On the contrary, feeding your shark foods outside of its diet may lead to stress. By sticking to your shark’s diet, you will ensure your shark reaches its full potential size. 

Other sharks in the tank 

Sharks can be very territorial, especially in the presence of another shark. If you have a territorial shark, it may have the instinct to starve other sharks or fish in your tank. 

This will become a tank size issue when it comes to eating and stress. 

You will often find that with certain species of sharks, there is one dominant shark and a “lesser” shark. Sharks of this nature tend to starve other sharks in the aquarium to maintain dominance. 

The passive shark will be starved into a restricted size. This can eventually lead to death if malnourishment continues. Behavior such as this is common among Red Tail Sharks. 

Diet preferences

Faster and bigger sharks require more feeding times throughout the day. Finding how often your shark eats will give you more insight into the size of your shark. 

Sharks can feed either at the surface or bottom of the tank. Pay attention to where your shark likes to feed. A bottom-feeding shark may go to the top of the tank if the food is there. 

Check your fish food selection to find if it is for surface or bottom-feeding fish. 


A malnourished shark that is not receiving the proper nutrients for its diet will be stunted. Growth will be slower than normal. 

A shark’s growth can be stunted if it is not receiving enough food or is not receiving the correct food. A great element is that these forms of fish are not fussy eaters. 

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Freshwater sharks will eat almost anything and, if dominant, will not miss a meal. They also prefer different forms of food. 

You can always turn your shark’s size around if you notice restrictions on its size due to a lack of diet selections.

How to choose the right tank for our shark? 

How to choose the right tank for our shark? 

Your shark species is the main factor in determining the size of a shark. 

A shark’s adult size is determined by its species’ average size. It is a mistake to go to the pet store and pick a shark that you have not thoroughly researched. 

Not all sharks grow to the same size or at the same rate.

Gather information

Your local pet store or local shark grower can give you the details on the type of shark you have. Make sure to ask: 

  • What is your selected shark’s maximum adult size?
  • What is the minimum tank size your shark will require?
  • What type of tank environment is best for your shark?
  • What are the best foods for your shark to eat, and how often?
  • Is your shark a surface or bottom feeder?
  • Does your shark like to be alone, or is company welcome in the tank?

Tank settings for sharks to grow.

Some shark species require more lighting. Lack of lighting can prevent growth and other vital ingredients for your shark’s health. 

There are sharks that require more heat than others, sharks that are more comfortable in a current, and sharks that like to be alone. 

While there is no sure way to determine if your shark is too cold or does not like the water, it is best to check with your local pet store for information on the appropriate conditions in your personal aquarium. 

Uncomfortable living situations could result in a lack of motivation for your shark to grow. Give your shark a reason to grow by making the environment ideal.

How to get your shark to grow in a fish tank?

How to get your shark to grow in a fish tank?

Maybe you have a shark in your fish tank and notice your shark’s growth may be compromised. 

If you want to get the maximum size from your shark in a fish tank, it takes three simple steps. These steps will ensure your shark grows to its maximum size.

Research your shark before purchase. 

This is the best way to determine how big your shark will grow in your fish tank. 

Adult size charts will give you an overview. Your research will determine if your shark needs more space or different neighbors. 

Get to know your shark. 

Whether you are considering a shark for a new fish tank or an existing one, check first to see if the shark you are anticipating is the right one for your aquarium. 

If you already have a shark, get to know the preferences of that shark based on the size components outlined here.

Comparing the needs of the shark to its living situation will let you know how big your shark will get in a fish tank. Check for stress levels and issues of growth stunting. 

Extending your tank size will not extend the size of your shark. It will help ensure an environment for growth. Paying attention to your shark’s species, behavior, environment, and diet will help your shark to grow.