Best Betta Fish Tank Size: Factors to Consider

Sharing is caring!

Are you considering getting a Betta? Many first-time fish owners make the mistake of purchasing the wrong tank size for their fish.

With the right tank size and care, Bettas can be a colorful and entertaining addition to your home.

betta fish tank size

So, before you buy your first Betta fish tank, let’s learn about the factors that determine the ideal tank size for betta fish.

What Is the Ideal Betta Fish Tank Size?

Bettas are tropical freshwater fish that hail from Southeast Asia. They can usually be found inhabiting shallow ponds, puddles, or rice paddies, where they hunt for food and create bubble nests for future fry.

Sadly, pet Bettas are often kept in bowls or containers that are too small for them to be healthy.

While Betta fish can survive in small bowls or jars, they thrive in larger tanks that provide ample space to swim and explore.

What is the ideal Betta fish tank size, you may ask? Well, the ideal Betta fish tank size is always the largest tank you can afford and have the space for at your home.

Betta Fish Tank
Source: @neilthebetta

Actually, since Bettas are used to jumping from pond to pond in the wild, there’s no such thing as a Betta fish tank that’s too big.

For beginners, at least 5 gallons is recommended, but if space permits, a 10-gallon tank would be even better.

With a larger tank, there is a greater volume of water which can dilute toxins and provide a more stable environment for your fish. In a smaller tank, it can be more challenging to maintain a stable water temperature and water quality.

Keep in mind that Betta fish are active and require proper filtration and heating to maintain a clean and healthy environment, regardless of the tank size. They also need tank lighting in order to regulate their natural rhythm.

What Is the Minimum Tank Size for Betta Fish?

Betta Fish Tank
Source: @bei_chobi_ch

Betta fish need a minimum of 2.5 gallons of water to live comfortably.

Some fishkeepers claim that Bettas can live in a 1-gallon tank or even less, but this comes with severe restrictions.

For one, most 1-gallon tanks on the market are much too small to support a filter or heater, which are essential for maintaining good water quality and temperature.

Unless you have a complete aquarium set, you’ll have to:

  • Do a daily water change
  • Watch your Betta during feedings to remove any uneaten food
  • Siphon out their droppings every day

For many beginners, this is too much of a hassle and not worth the effort.

Additionally, Bettas aren’t meant to stay in such a small container. Out there in the wild, they have a vast, open space where they’re free to explore. In a cramped 1-gallon tank, they’d feel trapped and stressed out.

Some may say, “But my neighbor kept her Betta in a 1-gallon bowl, and it survived.”

There will always be exceptions to the rule, but that’s all they are: exceptions. For every Betta that managed to survive for years in a 1-gallon container, it’s likely that there are 10 more out there that passed away prematurely.

Also, keep in mind that just although Bettas can tolerate small or shallow waters for short periods of time, it’s only because they’re waiting for the next rain that can take them someplace else. In a 1-gallon tank, there’s no hope for escape, but the Betta doesn’t know that. It’s arguably a cruel way to keep a fish.

If you already got a 1-gallon tank, though, don’t worry. It’s a common misconception that Bettas can live in a 1-gallon tank, so you’re not the only one who thought the same way. Luckily, you can always move your Betta to a larger tank. A 2.5-gallon would be a nice choice, and it’s quite affordable, too.

The Best Betta Fish Tank Size Options

In this section, we’ll discuss the pros and cons of different tank sizes for Betta fish.

1.5 Gallon Tank

1.5 gallon tank

As mentioned above, we don’t recommend a 1-gallon tank for Betta fish due to the amount of maintenance it requires. Also, a tank of this size will severely limit their ability to explore and exercise, leading to boredom and potential health issues.

Sure, it’s cheap, has a small footprint, and is easy to “set up,” but it’s really not suitable for keeping fish long-term.

Overall, although a 1-gallon tank can be a possible temporary home for a Betta, upgrading to a larger one will provide better living conditions and a better quality of life for your fish.

1-Gallon Tanks in the Market:

  • Tetra GloFish Betta Aquarium Kit 1.5 Gallons: This tank is marketed as the “perfect starter tank.” The quality is good since it’s from Tetra, after all. That said, you just need to add a few bucks, and you can get already get a 2.5-gallon aquarium kit, which is much better for your Betta.
  • PENN-PLAX NuWave Betta Fish Tank Kit 1.5 Gallons: Another complete aquarium kit that’s priced almost the same as the other one. It’s not bad, but trust us, you’re better off just getting a 2.5-gallon.

2.5 Gallon Tank

2.5 gallon tank

A 2.5-gallon tank is the bare minimum size for keeping a Betta healthy. In this tank, they won’t have as much space to explore, but at least their water quality will be easier to maintain because there are already filters that can fit in this size.

That said, it may be hard to find a heater that can comfortably fit inside a 2.5-gallon. Bettas are tropical fish, so you need to provide a heater if you live in a cold-weather climate.

Best 2.5 Gallon Tanks for Beginners:

  • Koller AquaView 2.5-Gallon Fish Tank: For just $5 more than the 1-gallon kits, you already get a complete 2.5-gallon tank with a power filter and LED lighting. It’s as “plug-and-play” as you can get.
  • Aqueon LED MiniBow Small Aquarium 2.5 Gallons: A premium choice, but the price reflects that. This complete aquarium kit has Aqueon’s SmartClean Technology that allows you to finish your water change in 2 minutes.
  • Tetra LED Cube-Shaped 3-Gallon Aquarium: Technically not a 2.5-gallon, but it’s a good option nonetheless. This 3-gallon tank also comes with a power filter and a clip-on LED light, plus a transparent cover to prevent your fish from jumping out.

3.5 Gallon Tank

3.5 gallon tank

A good size for a Betta tank if you want a little more space. With 3.5 gallons, you can fit most hang-on-back filters and even heaters.

Although you can technically make a planted tank out of a 2.5-gallon, it’s easier to do with a 3.5-gallon. The substrate takes up too much of the already limited space in a 2.5-gallon, so you can plan your own layout better with a slightly bigger tank.

Not to mention, with a 3.5 gallon, you can add some decorations to create hiding spots for your fish. This can give them a sense of security and can help reduce stress.

Best 3.5 Gallon Tanks for Beginners:

  • Koller AquaView 3.5-Gallon Aquarium Starter Kit: Another complete kit from Koller. The entire line is honestly great for beginners on a budget who don’t want to experiment with their own setups.
  • biOrb Flow 15 4-Gallon: If you’re willing to pay a premium for your first aquarium kit, this brand is a good choice. biOrb offers different tank configurations, all with their own lighting and internal filter. This curved glass tank may be more expensive than the other options, but it’s minimalistic, quiet, and easy to set up.

5 Gallon Tank

5 gallon tank

A 5-gallon tank is a great size for beginner fish owners. Tanks of this size are easy to find and come with all kinds of decorations. A 5-gallon tank also has enough space for a filter and heater and will make it easier to keep the water quality high.

However, if you want to add Betta tankmates like shrimp or snails, a 5-gallon tank may not be big enough to house them all. Each pet you add to a tank adds to its bioload. A smaller tank won’t be able to handle the same bioload as a larger tank, which means you’ll need a good filter to make sure that everything stays safe.

Best 5 Gallon Tanks for Beginners:

10 Gallon Tank

10 Gallon Tank
Source: @shawnasevigny

A 10-gallon tank is the best size for a Betta. It’s large enough that your fish can easily entertain themselves throughout the day. It also has enough volume of water that it can easily handle the bioload from any tankmates you may want to add.

Providing your betta fish with a larger tank allows you to add more plants and equipment, which in turn makes the tank more exciting and engaging for your fish. Make sure you choose decor that Bettas enjoy, like driftwood or leaf hammocks.

There are really no drawbacks to keeping a 10-gallon tank other than the price. It can be more expensive to keep a bigger tank, but in terms of effort and time, it’s much easier to maintain than a 5-gallon or a 2.5 gallon.

Best 10 Gallon Tanks for Beginners:

  • Aqueon Aquarium Fish Tank Starter Kit 10 Gallons: You can’t go wrong with Aqueon. Not to mention, this starter kit even comes with a net, a water conditioner sample, a fish food sample, and–get this–a submersible heater.
  • Marine LED Aquarium Kit 10 Gallon: Another great option for Betta owners. This 10-gallon tank is a complete kit, which means you don’t have to worry about buying the other necessary equipment separately.
  • PENN-PLAX Water-World Radius Desktop Nano Aquarium Kit: PENN-PLAX offers a lot of great aquarium kits that are perfect for beginners. This 10-gallon is no exception. It’s well-made, comes with all the necessary equipment, and has plenty of space for plants and decor. Best of all, it’s a curved glass aquarium, which gives you an unobstructed view of your fish.

20 Gallon Tank

20 gallon tank

If you want to give your Betta an underwater paradise all to itself, then a 20-gallon tank is a fantastic option, particularly a 20-gallon long tank.

This size can accommodate all of the necessary equipment and decorations to make your Betta feel at home. Additionally, it has plenty of space, so you can add other tankmates, too. Bettas are incredibly territorial and usually don’t like other tankmates, but in a 20-gallon planted tank, it may be possible to give them some company in the form of small fish or invertebrates.

The only downside is that a 20-gallon tank can be expensive and very heavy. If you think you’ll be moving within the next few years, we really can’t recommend getting a 20-gallon tank. Also, if you want a 20-gallon long, they’re usually marketed towards reptile or amphibian owners, so you’ll probably have to set it up on your own.

Best 20-Gallon Tanks for Beginners:

Factors to Consider when Picking the Right Betta Tank Size

When selecting the right tank size for your Betta fish, there are a few key factors to keep in mind.

  • Betta variant: There are many different types of Betta fish out there, and some variants need more space than others. For instance, long-finned Bettas can easily get tired swimming, so some fishkeepers keep them in smaller tanks than their short-finned counterparts.
  • Tankmates: If you’re planning to add tankmates to your Betta tank, try to get the largest tank you can afford. It’s not just to handle the bigger bioload. Since Bettas can be aggressive and territorial, you want to make sure your Betta has plenty of space to claim its territory.
  • Budget: Obviously, bigger tanks are going to cost more than smaller ones. We always recommend getting the biggest tank that fits your budget. Still, don’t forget to factor in the cost of the other necessary equipment, like a filter and heater.

Also Read:


Choosing the right tank size is important, but it’s just as important to make the most of the size you have.

Even if you don’t have a big tank, there are still ways to make your Betta’s world more suitable, such as adding plants and hiding spots. By making sure that your Betta tank is safe, secure, and comfortable, you can guarantee that your beloved fish is living its best life.

Sharing is caring!

Leave a Comment