Do Bettas Prefer Long Or Tall Tanks? (With Recommendations)

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When I had to choose a tank for my future betta fish, the first question that popped into my head was whether I should get a tall or a long one. After days of research and a lot of confusion, I finally made the decision. In this article, I’ll discuss what it means to have a long or tall tank – the pros and cons of both options.

Bettas prefer long tanks over tall ones since it leaves them with more room to swim around. Long tanks also allow them to quickly surface and gasp for air when needed, without the risk of getting trapped on the bottom. Bettas also swim horizontally more than vertically, making long tanks ideal.

As we move forward, I will show you why getting a long tank for your betta fish is better. Then, I will discuss what tank I chose for my betta. If you’re in a hurry, I recommend the Tetra Aquarium 20 Gallon Fish Tank Kit (link to Amazon).

Also Read: Facts About Bettas

Do Bettas Prefer Long Or Tall Tanks?

Most aquarists know that each betta needs at least 5 gallons of water. But that doesn’t tell them whether the tank should be long or tall. There is a big difference between the two. A tall 5-gallon tank is not as appealing to a betta as a long one because tall tanks do not offer as much space.

Like most fish, bettas require as much room to swim and explore as you can give them. Tall tanks do not offer quite as much freedom. It is also worth noting that, in the wild, bettas live in shallow water. They spend more time swimming left and right than they do up and down.[1]

Therefore, a deep tank doesn’t have anything to offer them. Many aquarists have also noted that betta fish have a labyrinth organ, allowing them to breathe outside the water.[2] They will occasionally break through the surface to do just that.

A deeper tank makes this more difficult. Bettas can still reach the surface in tall tanks, but the process is more stressful. Additionally, taller tanks are more difficult to decorate because they do not provide as much room.

You can crowd the tank by simply adding one or two ornaments, a development that the bettas will hate because all fish hate overcrowding, regardless of whether that crowding is the result of plants, decorations, or other fish.

What Is The Ideal Tank Size For A Betta Fish?

Bettas require at least 5 gallons of water, but the ideal size for them is 20 gallons. Since bettas are relatively territorial, they require a lot of space. Smaller tanks would incite aggression and stress, potentially shortening the fish’s lifespan and deteriorating its health.

Many aquarists believe that bettas can survive in cups. This is because some stores keep their bettas in cups. Yet, they do this to showcase the colors of the bettas; it isn’t an ideal setup for them. Bowls are no better. They do not provide adequate room for betta fish. The creatures are intelligent and adventurous, and a bowl doesn’t afford them the room they need to explore.

More importantly, bettas are more than capable of jumping out of their tanks.[3] This is why lids are essential. You have to keep their tanks covered to prevent them from escaping. But you can’t do that with bowls. They are too small.

Covering a bowl would result in an oxygen deficiency. Five gallons is the smallest tank they should live in. Some people will argue that the fish can live in 3 gallons.[4] They are not wrong. A betta can survive in a tank as small as 2.5 gallons. But it won’t be happy.

Bettas can live for 3-4 years in captivity. However, forcing them to live in a cramped environment will lower their lifespan. You have to give them five gallons of water. And that is only for a single betta. Ten gallons is better.[5] But if you don’t have a choice, five gallons will do.

If you want to keep more fish, you should get a bigger tank. On that matter, feel free to check this article, where I discussed how many bettas should be kept in each tank size. I went all the way from one gallon and gradually climbed to seventy-five gallons. 

What If The Aquarium Is Too Small For My Betta?

Forcing multiple bettas to share a small tank is a recipe for disaster. You can expect the following:

1. Toxins Will Quickly Spike

First of all, maintenance is going to become an issue. The problem with small aquariums is that it doesn’t take long for the concentration of waste and toxic chemicals to rise. The volume of water is so small that you have to clean the tank frequently to prevent ammonia from poisoning the fish.

The smaller the tank, the more difficult it will become to keep the waste and ammonia out of the water. It can be done. But it takes a lot of time and effort. You have to keep changing the water. Don’t forget that you cannot attach efficient filters to bowls and cups. The chances of a betta dying in a small aquarium are very high.

2. Your Betta Will Become Aggressive

A small tank is going to incite aggression. Bettas are the worst kind of fish to keep in a crowded space because they are territorial.[6] In a small tank, they will fight to the death. This can happen in a large tank as well. But it is more likely to occur in a small tank because the bettas cannot stay out of one another’s territory. 

Females are less aggressive than males. In fact, you can keep multiple females in the same tank. But if the tank is too small, the females will turn on one another. They will also attack fish from other species. If they have an opportunity to jump out of the tank, they will do so.

3. You’ll Have To Stick To A Small Number Of Fish

You cannot keep as many fish in a small tank. As was noted above, bettas are territorial. But you can keep multiple female bettas because they are not as aggressive. However, a small tank, especially a cup or bowl, will limit the number of fish you can keep. In most cases, you have to make do with one. A single fish is not as attractive or entertaining as an entire school of fish.

4. The Temperature Won’t Be Stable

The parameters are not as stable in a small tank. The external temperature tends to have a more drastic impact on the internal temperature of a small tank. Large swings in the temperature in your region could produce equally large swings in a cup or bowl.

Also Read: Can Betta Fish Live In Cold Water?

5. Small Tanks Are Difficult To Design

You don’t have as many options where the design of your tank is concerned. You can only add one or two plants and decorations because adding more would crowd the tank. To avoid making the small tank even smaller, you have to limit your choices to the smallest plants and decorations possible.

What Is The Maximum Tank Size For A Betta?

There is no such thing as a too-big tank for a betta fish. For fish, the bigger the tank, the better. They want to explore without restriction, and a large tank allows them to do just that. The size of the tank you will get will mainly depend on the number of fish you want to house.

5-10 gallons are too small for multiple fish. You need a tank of 11-20 gallons if you want to keep your bettas comfortable. Though, for professional aquarists, 20 gallons is still small. If you want a dozen fish, you need at least 40 gallons.

At the end of the day, you can get a 200-gallon tank if you want.[7] Your fish won’t complain. A massive tank has a multitude of advantages. For example, you don’t have to maintain it as frequently. Because it has so much water, it takes a while for the concentration of toxins and waste to grow.

Parameters like the temperature will remain stable as well. You don’t have to worry about changes in the ambient temperature causing sudden changes in the tank. That being said, large tanks are not always ideal. First of all, it may become more difficult to appreciate your fish. 

Some bettas have social personalities. They will emerge the moment they see you, responding to your presence by swimming in the open. But others may stay in hiding. Many aquarists with large tanks will tell you that they have fish they have never seen because their aquariums have too many hiding places.

This is why some people prefer to maintain smaller tanks. A smaller tank allows you to observe and appreciate your fish. If this issue doesn’t concern you, you should keep the demands of a large tank in mind.

However, bear in mind that a large tank needs a powerful filter. It also requires a pump that can agitate the water sufficiently. Otherwise, oxygen deficiencies are going to plague the aquarium. The heater is just as important. If it isn’t powerful enough to heat the tank uniformly, the heater could create fluctuations in the temperature. Fish hate fluctuations.

It might be better to buy a small tank that fits the number of bettas you want to house. Your bettas would appreciate an unnecessarily large tank, but your wallet won’t.

Do Betta Fish Live Longer In Bigger Tanks?

Bettas usually live longer in bigger tanks since the parameters of the water are more stable. The water temperature remains casual, and the tank’s volume is more than sufficient for all the fish to establish their territories. That will prevent them from becoming aggressive or fighting each other.

Some people think that a tank’s size will affect a betta’s size. That is to say, if the tank is small, the betta will remain small. If the tank is big, the betta will grow to its full size. But that isn’t true. In some cases, the stress caused by a small tank may stunt a betta’s growth.

But in most situations, it will grow to its full size. The tank size is unlikely to affect the betta’s size. On the other hand, the tank size will definitely affect the lifespan of the betta. A betta fish can live for 3 to 5 years in an aquarium.

Keep in mind that the bettas you buy from the store are not always young. The age of the betta when you buy it will determine how long it will live in your home aquarium. If you purchased a juvenile fish, you could trust it to survive for 3 to 5 years in the tank.

But if the tank is too small, the stress will reduce the betta’s lifespan. It will manifest signs of stress such as lethargy, loss of appetite, and discoloration. You could lose it in a year or two. If your betta presents one of those signs, consider replacing the tank immediately.

What Tank Should I Get For My Betta Fish?

I highly recommend the Tetra Aquarium 20 Gallon Fish Tank Kit (link to Amazon). It’s an all-inclusive kit that comes with everything you need: a tank, a filter, and a lighting system. It also comes with artificial plants, a substrate, and other decorations. 

For the money you’re paying, you get the best in the business. The tank is large enough to hold a dozen fish comfortably. And they can swim freely because the aquarium is wide enough.

To add to that, you don’t have to worry about having oxygen deficiencies since it comes with a decent filtration system.

I also recommend considering getting the API Freshwater Aquarium Water Master Test Kit (link to Amazon). That bundle will accurately measure the pH, ammonia, nitrates, and nitrites in your aquarium. Monitoring the water parameters is vital when it comes to betta fish.

These are the numbers you should aim for:[8]

  • Water pH: 6.8-7.5
  • Temperature: 76°-85° F (24°-29° C)
  • Ammonia and nitrites: 0 ppm.
  • Nitrates: below 20 ppm.

If the pH is too low or the toxins are too high, I suggest conducting more frequent water changes. As a rule of thumb, I replace 15-20 percent of the water weekly. Smaller tanks require more drastic changes and vice versa.

Also Read: Why Is My Female Betta Making A Bubble Nest?


In the end, a bigger and longer tank will benefit your betta. It allows the fish to establish their territories without coming into conflict with other bettas in the tank. You may not think that a few ounces of water matter when it comes to tank size, but they do matter to your betta’s health and longevity.

The larger the tank, the more comfortable and secure your betta. As stated in this article, a 20-gallon tank is ideal. In this one, you can easily grow up to four females and one male betta fish, creating an exciting environment.