Minimum Tank Size for Betta Fish

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One of the most important decisions that a future betta fish tank owner has to make is how big an aquarium they are going to buy.

The first thing an owner has to consider whether they are planning to have a betta fish on its own, or if they are going to have more bettas or other fish together with it. The general consensus is that 2 gallons of water per betta fish should be enough.

Although it might be wiser to invest a bit more and buy a larger tank. That can come handy in the future if you will be planning to expand your fish family, or if you intend to keep two bettas or more, or even other fish.

If you plan to own other fish with the betta, then generally, a larger tank is a better choice.

In this article, we will take a look at the minimum tank size for a betta fish, and everything about the tank requirements of the betta.

Remember, bettas can be delicate about their tank and may become territorial. They are also not going to be happy if you try to cramp them into a small container such as a small fishbowl.

Setting Up a Betta Fish Tank

Here is how you can get started with setting up the tank for your betta.

First, you will have to choose the right tank and the fish for your tank. If you opt for a betta fish, then a 2-gallon tank is the absolute minimum requirement. However, a 5-gallon tank is a bit more appropriate for the betta if you choose to have plenty of vegetation and other accessories, or if you decide to get a new fish in the future.

The next thing you should consider is the filtration. This part is absolutely essential; you can’t go wrong with choosing a good filter, and it will definitely improve the quality of life. Here, you will also need to choose a heater for your betta tank, and the substrate.

A heater is recommended for betta fish tank as they require slightly warmer waters. As for the substrate, small or smooth gravel is probably the best option for bettas. Also consider the vegetation – live or plastic plants will do well, and also consider the lighting system.

Next, setting up the tank is pretty easy, if you have everything ready. Here are the steps.

  1. Clean every part of the equipment. The tank, the plants, and other equipment that could contain bacteria or debris. Also, think about the spot where you will place the tank: is it even, does it get too much sun, or is it underexposed.
  2. Install the filter. Usually, installing the filter is not that hard, and you can always look at the instructions included. Don’t turn it on until there is water in the tank, though.
  3. Add gravel. The next step is to add the gravel. Of course, it should be cleaned and rinsed before it is put into the tank to prevent filter clogging.
  4. Set up plants. The next step is to add the plants into the gravel. Remember to rinse the plants before you put them inside.
  5. Condition the water and add it in. Don’t forget to condition the water with a conditioner, which will get it rid of harmful chemicals such as chlorine. Excess chlorine can harm your bettas. Next, once you condition it, fill up the tank. The water level should be slightly below the edge of the tank.
  6. Turn on the filter and the heater and prepare the water. The last step is to prepare the water for the bettas. Heat it up and filter it, and perform a fishless cycle. Once this step is done, you can add the fish.

Maintain Your Betta Fish Aquarium

Maintenance is essential for keeping your betta fish happy and healthy. No matter what the size of your tank is, you should always try to keep the water as clean as possible to prevent diseases and health issues, and to improve the quality of life for the fish.

You should try to perform maintenance checks once a week or once a fortnight. The maintenance checks include:

Based on the findings from the checks, you should perform maintenance once a week. It doesn’t take too much time, but the long-term benefits of this are extraordinary. The maintenance work includes:

If you do regular maintenance, then you can expect healthier bettas. It is probably the most important aspect of keeping your bettas healthy.

How Many Bettas Can You Keep in a 10-Gallon Tank?

We have already noted that bettas require at least 2 gallons of water to live normally. Although bettas can get territorial, if they have enough space that should not happen. If you want to keep more bettas together, remember that keeping male bettas together is not the best idea, as they can get aggressive with each other.

Keeping females together is more recommended. If you keep one male and three or four females, that can be a good thing. For a 10-gallon tank, you can keep 3-5 bettas together. However, the more bettas there are, the more space they will require. If you want to keep 5 or more bettas in the same tank, then a 15 or a 20-gallon tank would be a better choice.

If you plan to have other fish with the bettas, then you should consider the type of fish you will be keeping, and how many of them. Remember that male bettas can get aggressive towards other fish, so having a larger tank is better.

Do Bettas Like Small or Big Tanks?

In general, bettas prefer to have bigger tanks rather than small tanks. The consensus is that a tank can’t be too big for a betta, unless it is too deep for the betta to swim to the surface. Remember that bettas like to swim towards the surface to get oxygen, so having a very deep tank is not the best choice.

On the other hand, a small tank can do a lot of harm to your betta. They prefer to live in larger tanks, and if you plan to have more bettas together, then avoid small tanks. The better choice would be to go for tanks that are too big rather than too small for bettas.

Can a Tank be Too Big for Betta?

No, it can’t be too big for a betta. A single betta will be very happy to live in a 10-gallon tank or even larger, if it is kept in proper conditions. Unless the tank is too deep, an aquarium can’t be too big for a betta.


Bettas are beautiful fish that like to have plenty of space. If a betta fish doesn’t have enough space, it might get stressed, and you might see some diseases starting to develop.

Having a betta in a 2-gallon tank or larger is the best option.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.

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