How Many Betta Fish In a 3-Gallon Tank?

If you’ve seen betta fish in tiny bowls at the pet store, it’s likely got you wondering—how many betta fish in a 3-gallon tank is permissible? You shouldn’t keep any betta fish in a 3-gallon tank because each fish should have at least five gallons of water. 

We understand this is a surprise and sympathize with your infuriation at realizing what little space pet stores offer their bettas.

Read on for more details about why bettas need five gallons of water and what can happen if you give them a smaller space.

How Many Betta Fish in a 3-Gallon Tank?

No betta fish should live in a 3-gallon tank. So, if you just brought home a shiny new 3-gallon tank, return it to the store.

Betta fish need five gallons of water per fish.

That measurement is a minimum. The more swimming space you offer your betta fish, the happier and healthier they’ll be. You should start with a 5-gallon tank for your fish as a rule of thumb.

Two Red and Blue Betta Fish

Issues That a 3-Gallon Tank Can Cause

By keeping your betta in a 3-gallon tank, you increase the chances of them suffering from stress and other health conditions.

Some of the most common issues associated with small betta tanks include:

  • Reduced water quality
  • The tank getting dirty quickly
  • Decor can cause the space to become even smaller
  • Not as much surface water

Surface water is essential for betta fish because they live on the water’s surface. Therefore, if a 3-gallon tank has a small opening, such as a vase, this creates even more issues for them.

Signs That a Betta’s Tank Is Too Small

If you already have your betta fish in a 3-gallon tank, you might notice one or more of the following behavioral or physical changes in them.

  • Jumping out of the water
  • Losing their color
  • Loss of appetite

Your betta fish may also become depressed. So, they might not respond to cues as they usually do when you walk into the room or offer them food.

The Dangers of a 3-Gallon Betta Tank

It’s hard to believe that a 3-gallon betta tank can be dangerous for your fish when the pet stores keep them in little bowls, but we assure you that’s the case.

Bettas rely on good water quality to survive. However, when their tank is too small, the ammonia from their urine builds up and can cause deadly consequences.

Of course, this can happen in 5-gallon or larger tanks too. However, even if you change your betta’s water every week or so, it might not be enough to prevent the water from having an ammonia build-up.

As if it couldn’t get worse, the presence of the toxin nitrite also happens when ammonia is present. Together, they can be a lethal combination for your fish, as they also alter the pH level.

The Lifespan of Bettas in Large Tanks

By keeping your betta fish in a 5-gallon tank or larger, they’ll have a chance of living up to five years old.

However, smaller tanks decrease the amount of dissolved oxygen available for them to breathe and other resources they need to survive.

Like humans, stress can cause bettas to suffer from various health issues. And it just so happens that one of the most significant stresses for bettas is living in a tank that’s too small.

How To Choose an Appropriate-Sized Tank for Your Betta

Now that you know a 3-gallon tank is too small, you might be wondering—what qualities should I look for in a betta tank?

Aside from ensuring the tank offers at least five gallons of space per fish, below are some other factors to look for:

  • A larger surface area at the top is more important than a deep tank
  • Long tanks are typically better for bettas than tall tanks
  • Tanks with lids are crucial since bettas can jump

Furthermore, make sure not to overstuff even a 5-gallon or larger tank with decorations. You should also ensure the decorations don’t inhibit the betta’s ability to swim around the water’s surface.

What If I Own a King Betta?

The information here doesn’t apply to king bettas, given that these fish are about twice the size of other betta breeds.

Therefore, if you have a king betta, it’s all the more reason not to buy a 3-gallon tank for them—they need a tank that’s at least ten gallons per fish.

As with all species of bettas, king bettas will appreciate the most giant tank you can give them.

Tips for Introducing Bettas to One Another

Betta fish got their name “Siamese fighting fish” for a reason. Unfortunately for fish in their tank, it means that many fish won’t fare well with a betta fish present.

So, if you buy a 10-gallon or larger tank where you can have one or more betta fish living together, follow the tips below.

  1. Pair females together in the same tank.
  2. Never put males in the same tank—they should always be by themselves.
  3. Males and females should never share a tank except for mating.
  4. Have a backup plan to separate the fish if fighting occurs.

It’s crucial that you stay around your tank when you initially introduce your betta fish to each other. However, fights can happen at any time, so look out for fish injuries and act if needed.

Fish and Invertebrates That Bettas Get Along With

In many cases, introducing a different species of fish or invertebrate to your large betta tank is a better option than pairing your betta with another betta.

Below are some species that usually make a good match for betta tanks.

  • Malaysian trumpet snails
  • Corey catfish
  • Kuhli loaches
  • Ember Tetras

Before introducing any of these species to your betta tank, make sure your tank is large enough to accommodate them comfortably.

Settling Your Betta Into Their Ideal Tank

So, how many betta fish in a 3-gallon tank is safe? The answer is none.

Betta fish require at least five gallons each to have enough room to roam the water’s surface, have dissolved oxygen, and sufficient volume to prevent ammonia and nitrite build-up.

Now that you know how to arrange your betta’s tank so that they’ll live a happier and potentially longer life, we’ll leave you to start making changes to your betta’s living arrangements.

Have Another Tank Size You’re Looking for?

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