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Shark Growth Rates When Kept In A Fish Tank!

The popularity of keeping “sharks” in aquariums is at an all time high and the number of people adding various species of fish marketed as sharks or even actual sharks in their tanks is continuing to increase with each year that goes by.

With many of these purchases being fuelled by the incorrect information that a shark is unable to outgrow its aquarium, we wanted to publish this dedicated article going over the shark growth rate in fish tanks to try and help our readers avoid making the same mistake that so many other people have made over the years.

You also have to realize that there are a number of species of fish that can be fine to keep in your aquarium or fish tank that will not grow too large but are often marketed as sharks as a marketing technique.

This can be one reason that people tend to believe the shark in a fish tank growth myth as many of the fish they see in pet stores marketed as sharks are tiny but they do rapidly grow with many of them getting to as long as one foot in length when adults.

We usually see three commonly asked questions from people asking about keeping sharks in aquariums so we have decided to group them all together into this single article.

The table of contents below will make it much easier for our readers to quickly and easily skip to specific sections of the article to save you time.

Can You Keep A Saltwater Shark In A Fish Tank?

The majority of private fish keepers are unable to keep a real saltwater shark in their aquariums due to the sheer size and cost of maintenance of a real shark.

Some people within the fish keeping hobby do keep bamboo sharks but even then they require a large amount of maintenance so they should only be kept by people who are experienced fish keepers.

You can see the size of aquarium required for the more impressive shark species at the various public aquariums that keep live saltwater sharks.

They are huge due to the size the shark will grow to meaning that they require a massive amount of space and larger tanks have more problems meaning that your costs and time commitment are also drastically increased too.

Even a bamboo shark that is the most commonly kept real shark within the fish keeping hobby is able to grow to a size of around four feet as an adult.

This means that it will usually require a 175 gallon aquarium as an absolute minimum with most people who do successfully keep bamboo sharks opting to go with a 200 gallon aquarium or even larger.

“Baby Bamboo Shark” by PacificKlaus is licensed under CC BY-NC 2.0. To view a copy of this license, visit

Will A Shark Only Grow To The Size Of Its Tank?

The growth rate of sharks is not influenced by the size of their aquarium and they will continue to grow to the normal adult size for that species with some captive sharks growing even larger than normal due to having a reliable food source.

Even the smaller fish species that are sold as “sharks” will often grow to their normal adult sizes of around a foot in length without the size of their tank coming into play.

Now, the available food and the water conditions in the aquarium will come into play more than the actual size of the aquarium itself with poor water conditions and a lack of food being able to stunt the growth of a shark.

This presents a number of other risks to the shark though and will often cause problems that will also reduce the life span of the shark drastically so is never recommended.

There is a reason that there are so many public aquariums with the larger saltwater shark species in their tanks struggling to stay open as their costs of maintaining their shark tanks are just too high.

If they were able to consistently reduce the maximum lengths of the sharks they keep to drastically reduce their costs for maintaining their tanks then they definitely would do it but they require these huge aquariums due to sharks easily being able to outgrow their tanks.

What Sharks Can You Keep In A Fish Tank?

The bamboo shark is the only real shark that you can really keep in a fish tank and even then they can grow as long as four feet when fully grown.

There are a number of other fish species that are commonly marketed as sharks that are much smaller though while still having somewhat of a shark like appearance.

The most common one of these by far is the bala shark (also known as a silver shark) with many fish keepers picking them up due to their tiny size in pet stores and having shark in their name.

Unfortunately though, even bala sharks can still grow to a length of around one foot when adults making them a poor option for many beginner fish keepers who have smaller tanks.

Another common option is the red tail black shark that is very popular right now and unlike the bala shark, they tend to be much smaller but the red tail black shark can be very aggressive to smaller fish in your tank.

This causes problems with the red tail black shark bullying its tank mates with most people usually having to get rid of the fish or put it into a tank by itself.


That brings our article going over keeping a shark in a fish tank and how large it can grow to an end. We hope that we have helped our readers avoid some very common mistakes that we see people from the community making time and time again. These mistakes are so common that we see people reaching out about having bala sharks, bamboo sharks, or red tail black sharks that are having problems with their tank and needing advice on what to do with them. Always do your research specific to any fish species that you intent to add to your tank as they really can be hidden surprises that the pet store don’t make you aware of.