How Big Should a Betta Fish Tank Be? – The Best Size

If you’re wondering “how big should a betta fish tank be?”, I highly suggest a minimum size of 3 or 5 gallons (to give your pets more room). With this tank size, your betta fish might be able to live for approximately 3 to 5 years.

In case you want to opt for a smaller tank, such as a 2.5-gallon one, you should not do so since it might affect your fish’s health or even shorten their longevity. To discover deeper information, scroll down for more now!

Recommended Tank Size for Betta


Let’s get straight to the main point! A 5 or 3-gallon fish tank is acceptable for almost all kinds of bettas. However, you should prepare a 10 gallon one if you wish to offer your pets a comfortable living area.

Moreover, bigger tanks can also help you avoid fish waste accumulating so fast that it’ll make the whole place dirty quicker. So, feel free to opt for a larger/bigger betta fish tank size.

Although there is nothing such as a max size for a betta tank, you should refer to the betta minimum tank size as it can directly affect your pet fish. It’s because betta fish are quite active, which needs a lot of space to swim around.

Types of Bettas


There are around 73 different types (or more) of bettas, each with its own distinct appearance and swimming style. As a result, fish owners must select the appropriate tank shape/style for their pets.

Short-finned varieties (like plakat bettas) and long-finned ones (like half-moon bettas) swim at different speeds. Plakat bettas move quickly and love exploring their surroundings, whereas longer-finned species do not.

Based on this, the ideal tank size for bettas with short fins is 10 to 20 gallons. Meanwhile, long-finned bettas require only long and shallow tank designs.

Furthermore, the pets’ sizes also matter. If you want to adopt Giant bettas (around 6-7 inches in length), the recommended tank size for betta here is over 10 gallons. Conversely, you only need a 5-gallon fish tank for regular-sized bettas.

Things to Consider Before Choosing a Size Tank for Betta


1. Your Budget

Right after knowing more about the bettas, you should know how much is your expected budget for a fish tank. If you are able to have a 20-gallon tank, it would be great. Whatever option you end up choosing, you must stick to the guideline that the smallest size should be over 5 gallons.

2. Tanks’ Shape

I would recommend the rectangular tank, even though it obviously looks bigger and less cute than the regular fish bowl. It’s all because this tank shape will provide your pets enough space to swim and enjoy their lives. Besides, tank cleaning tasks will also take less effort.

3. Bettas’ Tankmates

Bettas, also known as Siamese Fighting Fish, are aggressive. Therefore, if you want to give your pets some “friends,” you should consider a bigger tank. Aside from several well-known sociable species, if you desire to keep a few bettas together, you must consider a larger tank size.

You can refer to a few famous cohabitants with bettas, provided that you pay attention to their tank requirements as well. For example, mystery snails (2 inches in length) need a bigger tank than a 5-gallon one. Meanwhile, ghost shrimps (1.5 inches in length) and cory catfish (1-2.5 inches long) require at least a 10-gallon tank).

Ideal Betta Fish Tank


In short, there are 6 main points to focus on if you want to create a perfect living area f0r your pet bettas:

  • Always choose the fish tank that is made of glass or acrylic materials (to avoid scratch and fog on the surface over time).
  • Pick a wide low tank (not a deep tank) since your fish is basically a surface dweller.
  • Remember to arrange some place for your pets to hide in order to replicate their natural habitat.
  • Never forget to employ a filter to maintain your tank water at around 76-81 degrees F.
  • Ensure the pH level inside your betta tank ranges from 6.5 to 7.5.
  • Choose the appropriate tankmate for your fish, such as shrimps or snails.

How to Set Up Betta Tanks?

Aside from knowing how big of a tank a beta fish need, there are other steps to take in order to set up an ideal betta aquarium.

Step 1: Find a place that you intend to put your betta tank in. Just ensure that it’s not too close to the direct sunlight or any heating sources. Don’t forget to consider what size tank do betta fish need at this step!

Step 2: Use tap water/purified water to clean the tank carefully. Avoid using diluted bleach solution or you will accidentally kill your pets.

Step 3: Employ the tank filter and heater.

Step 4: Build up the substrate in the bottom of your tank, 1-2 inches thick would be great.

Step 5: Do the decoration and add the plants into your tank.

Step 6: Put a plate on the substrate surface and gradually add some water in. Notice to leave 1-2 inches spare on the top of the tank so that your bettas can have more oxygen.

Step 7: Use a water conditioner to prepare the perfect water for your pet. Follow the guide on the product’s label strictly!

Step 8: Let your pet inside a bag/cup (together with the water from the pet store) and put the whole thing inside the new tank.

Step 9: Wait until the water temperature becomes quite equal before putting your beloved fish into their new home.

Frequently Asked Questions


How many gallons or how much space does a betta fish need?

Each betta will need around 2.5 gallons of water to live comfortably, meaning you need a betta fish tank size of 19 liters. This benchmark might be influenced by the actual size of your fish. Therefore, it would be best if you choose a tank three times bigger than your bettas’ sizes.

What happens if the fish tank is too small for betta fish?

It’ll probably decrease betta fish’s lifespan. To be more specific, a betta can live around 3 to 5 years in a comfortable tank; but, it will live only around a year in a 1-gallon tank.

Do betta fish enjoy big tanks?

Yes, they do. In a bigger tank, betta fish will live longer and be healthier. Therefore, a devoted fish owner should always try to offer their pet fish a larger living area.

What size tank is too big for a betta?

If your tank is larger than 5 gallons, then it’s great enough for your fish because there’s no size of tank defined as too big for a betta.


Not only did I answer your question of “how big should a betta fish tank be”, but I have also offered you lots of information about the tank setup and how an ideal betta fish tank should be. Therefore, I truly hope that this article has been helpful to you.

Are there any other questions about this topic? If you have, feel free to comment below and I will assist you immediately. Thanks a lot in advance.