Why Are Betta Fish Tanks So Small? (Answers 2022)

Many fish owners opt for Bettas for their bright colors and their long flowing tails. The fighting fish, in most cases, needs keeping away from other fish. As a result, aquarium sizes don’t need to be so big, and this leads to a common question like the one below:

Why are Betta fish tanks so small?

You find a couple of reasons why you find Betta fish tanks to be on the small side. One of the first is, Bettas are bought from stores in small containers, and the new owner is given the impression this is how they should live because of their nature. Second, Bettas are anabantids and can breathe from the surface of the water, rather than through their gills.

In theory, Bettas make use of their labyrinth organ and can breathe from the surface. Because of this, there is no need for air pumps. It is because of this; you see Bettas on desks in flower vases and all manner of small Betta fish tanks.

In reality, even though they can breathe from the surface, and there is no need for an air pump or aquarium filter. A scenario of this kind doesn’t mean it is the best one for your fish. Carry on reading, and you will learn more about what the ideal size and conditions should be for your Betta fish tanks.

Betta Fish

Why Pet Stores Keep Bettas in Small Containers

It is the fighting nature of Bettas, why pet storeowners keep them separated. The small containers are because they can fit more into their store, and because of the breathing capabilities of the Betta, it is all they require.

There is no other reason for doing this, and it is this that leads to the misconception any small fish tank is suitable to house a Betta fish.

In summary, Bettas do much better in a tank that is at least 2.5-gallons in size, and it has frequent water changes. Water temperatures for this also need to be around 76 to 82 degrees fahrenheit. Even these conditions are the worst these fish should endure, and the preferable is a bit different if you want to keep a healthy fish.

How Large Should a Real betta Tank Be?

Even though many people say, Bettas can live in small tanks. The ideal size should be nothing less than 5-gallons. These tanks offer many benefits over something smaller. Betta can swim more, and it is the beauty of watching them swim, that draws people to have one in the first place.

Even 5-gallon tanks are considered, on the small size once you begin adding plants and substrates. The other thing to know is that the smaller the container, the harder it is to control the conditions of the water.

Bettas are known to breathe from the surface of the water; however, without filters, the water condition can deteriorate. This is the second misconception of keeping Bettas in a small tank.

Aquarium Filters for Bettas

Many people think Bettas can handle dirty water, and if this were the case, you wouldn’t need to make continual water changes if they were in a small tank. Water may be shallow in their natural habitat, yet it is far from dirty.

It will comprise an ecosystem that works together, and their surrounding water will be full of oxygen. Bettas jump from puddle to puddle as they search for large bodies of water in the wild.

Filters in your Betta tank will deliver a better source of oxygen to your fish. If you decide not to use a filter, then you need to prepare for a water change every three days. The amount you need to change is around 40%. In this scenario, you can forget to do this, or you find it tedious to keep changing the water so often.

When selecting an aquarium filter, you need one that creates a gentle flow, as Bettas are not keen on turbulent water. It is a straightforward resolve, and you can add a pre-filter, or a sponge at the outlet to break the flow of water.

Larger tanks can also be a solution because the water will settle once it begins to reach halfway across your tank.

Aquarium Filters for Bettas

Tank Heaters for Bettas

Bettas need water temperatures between 76 and 82 degrees fahrenheit. This is the water temperature from their natural habitat. In a small Betta fish tanks, you won’t be able to use an aquarium heater, and it can be harder to maintain the ideal temperatures without one.

When using tank heaters, you need a thermometer placed at the far end of your Betta fish tanks. By doing this, and you have a temperature reading of the ideal at around 78 and 80 degrees fahrenheit. The remainder of the tank will be in the range for your fish.

Small Betta Tanks are Easier to Clean

Many fish owners who choose to have one Betta think the smaller tank can save them a large amount of work. Anyone who thinks small tanks are easier to keep clean is mistaken.

Once you select larger Betta fish tanks and add in a filter, then you will build an ecosystem for your fish to thrive in. You can find larger tanks take less than an hour of maintenance every few weeks.

When you compare this to the water changes every three days for a tank without a filter, this is a huge difference. However, this isn’t all you will face when using a small tank; and when you are setting out, many people neglect to mention this.

There will be plenty of solid waste in your Betta fish tanks, and this can range from uneaten food to fish waste. There is also the chance of algae growth, and once you have a combination of these, then water quality will suffer.

If the water conditi0on starts to turn bad, you may find your Betta suffering from fin rot, or they stress out. A sign of stress is when fish swim backward and forward along the glass. It is as if they are looking for something, but they are unable to find it.

Tank Heaters for Bettas

Buying a Healthy Betta

No one should purchase a Betta fish until their tank has finished cycling. Doing this means you can add your fish to your aquarium, without it sitting in the container it travelled from the store in, for too much longer.

Storeowners neglect to mention many Bettas die because they are in small containers with poor water conditions. It is a lucrative business, and fish, which die once they sell them, is still money in their pocket. Many die which no one sees, and even more can die within the first few days to a week because of illness or stress.

Here is how to check your Betta is in the best of health possible in the store:

  • Fins should be undamaged and the body a bright color
  • The betta is swimming around as best as it can in a small space
  • If the Betta is actively showing signs of aggression to other fish, or when you look at it
  • There are no signs of deformities like scales missing, misshapen fins or eye problems
  • The fish has no white dots or has any foreign substances on its body (disease)

Once you find a healthy fish, you may be tempted to drop it directly into its new home. However, the water will be different, so refrain from doing this, and take a little extra time to do it properly.

Take the bag your fish is in, and place this into your aquarium water. This will gently warm the bag water until it reaches the temperature of the tank. You need to allow an hour for this to happen.

Once you are at this stage, you can add some of the tank water inside the bag, so it mixes. Once most of the water in the bag will be tank water, you can lower the side and let your fish swim into its new surroundings.


Although your Betta can survive in a smaller tank without a filter, it doesn’t mean you need to subject it to the same conditions.

One other thing Betta owners are led to believe is the fish should always remain in solitary. Under the right conditions, this is another myth you can shatter. A male Betta can comfortably live in a community tank, and you can even have female Bettas in the same tank.

Once you have an aquarium, which is large enough to house all these fish, you will quickly wonder why you ever considered keeping your Betta in a small tank.