What Is The Ideal Betta Fish Tank Size? (2024 Detailed Guide)

Dr. Mollie Newton
Published by Dr. Mollie Newton PHD| Senior Editor
Last updated: May 8, 2024
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If someone aspires to be an aquarist, incorporating a betta fish tank into their living area could be a captivating enhancement.

While these tropical fish can come with some important considerations regarding neighbors and tank size, these issues shouldn’t scare you away from having one betta fish in your life.

If you’ve ever wanted to look into a betta tank for yourself, aquarium size is one of the first things to consider.

In today’s article we’ll look at choosing the proper betta fish tank size, so read on to find out more!

Article Summary

  • The minimum tank size recommended for a single betta fish is a 5-gallon tank, which allows them enough space to swim and establish their territory.
  • Bettas do not grow to fill the space they’re in; they have a maximum size of about 5 inches regardless of tank size.
  • For two betta fish, responsible ownership is essential, and it’s important to prevent aggressive encounters and choose a tank size of 10 gallons or more.

The Natural Habitat and History of the Betta

Blue Betta Fish
Blue Betta Fish

Betta fish, also known as Betta splendens, originate in the tropical waters of Thailand and Southeast Asia.

These fish adapted to survive in the often variable seasons of these climates through the evolution of a specialized labyrinth organ that allows them to breathe surface air for several hours at a time.


Betta fish live in stagnant water. The natural environment of these labyrinth fish would be the warm water of a rice paddy.

These small spaces led to a fish that is naturally quite territorial, having to fend off other fish in order to maintain their own way of life.


The distant ancestors of these fish were Prussian Carp, which were initially bred for their large size and plentiful meat.

Over time it was noticed that they could be bred for their beautiful colors and fantastic fin shape and eventually they made their way to Japan to be bred as the koi fish we know today.


They are also referred to as Siamese Fighting Fish, bettas were often put on display in bet-upon matches to see which of two bettas would be the victor in a battle to the death.

These days this practice is seldom seen, much to the relief of the modern betta.

Western Market

The betta was brought into the mainstream Western market in the early 1920s, after many years of careful betta breeding in the east.

These fish were quickly picked up on as one of the most popular breeds for the home aquarist, and have remained that way ever since.

What Size Tank Do Betta Fish Need?

Orange Betta Swimming Near Water Surface
Orange Betta Swimming Near Water Surface

When you see a betta in most pet stores, it is kept in a small tank, sometimes even in tiny fish tanks that are more like a bowl than most aquariums.

This sets the average fish keeper up with the misconception that betta fish like to live in tiny, enclosed spaces.

This is not only wrong, but it can potentially hurt your fish in the long run! To give your betta a happy life, you must provide them with its needs throughout its lifespan.

Minimum Tank Size For Betta

Betta are active fish, they need enough swimming space to move around in. A smaller environment will lead to an inactive fish. The minimum betta fish tank size that I recommend for a single fish is a 5 gallon tank.

This is the ideal tank size for a single betta because it allows them plenty of room to swim and feel like they have an adequate amount of territory. Having a filter will also help keep the environment healthy for your betta.

While we can’t provide whole rice paddies for our single betta fish, we can at least give them the space they deserve!

Tank Setup

Similar to their natural habitat, bettas prefer warm water temperature and slow moving or still water.

When looking at a betta tank setup that includes tank mates, we recommend an additional gallon per each extra inch of fish.

Keep in mind that these are only the recommended minimum size, and you can typically never go too large when trying to provide enough space for tank mates.

Do Betta Fish Like Big or Small Tanks?

While smaller tanks can work, the bigger your tank the better! In reality, as long as you’ve met the minimum 5 gallon tank requirement, the best betta fish tank is the one that suits the space you have available.

A tiny bowl is no way to keep a betta happy.

Not only will they lack the proper amount of room to swim, it can seriously affect your fish’s health as they become more lethargic over time.

Community Tank

Bettas in Display Tanks
Bettas in Display Tanks

That being said, If trying to build a community aquarium with multiple fish species, it is important to factor in that additional 1 gallon tank per 1 inch of fish recommendation.

Some fish and invertebrates may require more or less than this, meaning larger tanks may become necessary.

Speaking of a large aquarium, the Oscar cichlid, for instance, can require a minimum of a 100 gallon tank for an individual fish!


Make sure that you know the requirements of all neighbors in your tank before putting everyone together.


A good place to start is by doing your proper research when looking for the ideal tank size for your betta.

When looking for a new betta fish tank, I recommend that betta owners begin at nearby pet stores, a good guidebook, or with the breeder from whom they purchased their fish.

Don’t be afraid to ask around different local fish stores, not only will these sources have a great depth of knowledge on the requirements of their specific fish, but they’ll have their own tips and tricks for helping your betta lead a healthy life.

Improper Breeding

If you suspect improper breeding techniques were used for your betta, don’t be afraid to mention this to the breeder.

A seller who is unwilling to be transparent on every part of their process may be using cruel practices to get as many fish as possible.


For instance, if it’s known that the genetics of the betta breed you’ve bought has a tendency to react poorly to colder temperatures, ensuring the surrounding air temperature is high enough can be a great way to keep healthy fish.

Things To Consider For Your Betta Fish Tank

Arranging Fish Tank Decoration
Arranging Fish Tank Decoration

Along with the general size of betta tanks, there are a few other important things to look at when choosing your first betta tank:


Considering that betta fish tanks are not necessarily the natural world they are used to, it can help to mimic some of the qualities of their original home.

Bettas prefer lots of swimming space, and as such a larger tank in the shape of a rectangle can give them the most horizontal swimming room.

Even a smaller tank (again, at least five gallons) can be made more comfortable by being in the proper shape.

Apart from the aesthetic value, round tanks lose a good amount of swim space because of their geometry.


While they may not care in particular about the looks of the inside of the tank, bettas really enjoy being able to hide and feel secure.

They love having little nooks and crannies, along with objects to break line of sight between themselves and others. Good options include caves, ships, and alcoves. Betta toys are also good addition to your betta tank.

Try Different Types

Fish Tank
Fish Tank

Considering your fish’s lack of taste, feel free to experiment with whatever lights, designs, colors, and shapes you like the look of!

As long as they give necessary places for them to hide and feel safe, they’ll assist with keeping fish happy.

As such, good decorations are those such as artificial caves, ships, and other objects that have dark room for your fish to hide or sleep in. With these decorations, you might usually find your betta hiding or spending more time at the bottom.


Keep in mind that just because they’re hiding this doesn’t mean something is wrong, but that they have a need that you can now meet with proper aquarium setup!


Given their history moving from one puddle to another in search of larger territory, bettas are known as avid jumpers!

While they can indeed survive off of surface air thanks to their specialized labyrinth organ for several hours, lying on the floor is not a good place to find your betta at the end of the day.

Here’s a cool video to show how jumpy a betta can be…

Jumping Betta Fish

Using a lid is a great way to ensure that your bettas won’t accidentally hurt themselves by jumping out of the tank.


Whether you add live plants or plastic plants, bettas love having these non-threatening neighbors in their tank.

The rice paddies that they originally come from allowed for lots of line of sight breaking and hiding within plants, and the presence of these can make a new betta much more comfortable.

Java ferns, anubias, and moss balls can all make great choices for betta community tanks. These are all hardy, easy to care for options that have the added benefit of being beautiful themselves.

As with fish and invertebrates, it’s important to keep an eye on the health of your aquarium plants.

Just because they don’t eat or move doesn’t mean that betta don’t have their own specific requirements for water quality and water parameters.

Tap Water

Fish Tank Being Filled with Water
Fish Tank Being Filled with Water

If using tap water for your tank, you may need to consider the use of a water conditioner to reach the proper conditions for plant growth. Before putting plants, make sure to check the water parameters using an aquarium test kit

Also ensure that the plant you choose needs the same water temperature (75-80 degrees Fahrenheit) as your bettas.

While more plants won’t need a bigger tank, it does mean keeping closer track of their health.

Fake Plants

Fake plants will need to be cleaned on a regular basis to avoid mold and excess algae.

Likewise keep an eye on live plants for deterioration and death, as decaying plants and uneaten food can quickly lead to an ammonia spike in the tank if unchecked.

Do Betta Fish Grow To The Size Of Their Tank?

Blue and Orange Betta
Blue and Orange Betta

Contrary to popular belief, fish do not grow to fill the space they’ve been provided.

Betta fish will grow to a maximum of 5 inches in their lifetime, whether in a small bowl or bigger tanks.

Even goldfish, widely known as “the fish that grow to fill their space” will only continue to grow ½-1” per year, regardless of the actual size of the tank.

Good nutrition and water quality play much more of a role in this than a large or small aquarium.

Why Choosing A Tank Size Is Important

The primary reason for proper betta tank size selection is to ensure the right size tank for your needs.

If you’re looking into a more community-oriented tank with lots of different fish, definitely consider the need for a much higher water volume.

More fish will also come with the need for more filtration and water movement to prevent fish waste accumulation and to prevent diseases.

What Do Bettas Like In Their Tank?

Bettas like lots of area to swim, room to hide and break line of sight.

As such, adding in objects, decorations, and plants can go a long way to ensuring a happy, healthy betta.

When first setting up your tank, looking into a betta specific aquarium kit is not a bad idea for beginners.

This will typically include all of the things that a betta enjoys in one place, along with instructions on how to properly care for them over time.

What Size Tank For Two Betta Fish

Pair of Bettas
Pair of Bettas

First off, looking at a tank for two bettas comes with some important considerations.

Responsible aquarium ownership means knowing how your fish will behave towards others, and a large tank may not be enough to prevent a betta from attacking another new fish.

  • Two male bettas should never be in the same tank, as they will likely fight to the death over territory.
  • A male and female betta can work together, keeping in mind that if they breed the male betta fish may become aggressive towards the female after she lays eggs.
  • Multiple female betta fish can work in the same tank, often referred to as a betta sorority tank, but a close eye should be kept to prevent aggressive encounters.
  • When looking at large tanks for multiple bettas, look at the same water volume of a 5 gallon minimum per fish, so a tank of two bettas would need 10 gallons and so on.


Throughout today’s article, we’ve looked at what the most adequate betta tank size is, along with some other things to consider when setting up their tank.

We recommend a minimum of a 5 gallon tank for an individual betta, with a larger aquarium being a good consideration for more fish after that.

Remember that while a small tank may be cute, it might not be the best thing for your betta!

Feel Free To Share!

As always we hope that you’ve enjoyed today’s article and that it has answered some of your burning betta questions.

Feel free to share this information with any other fish fanatics in your life or anyone in the aquarium hobby, and we wish you the best of luck on your aquarium adventures!

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