Why Do Betta Fish Make Bubbles?

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Building bubble nests is a natural behaviour for male Bettas but why do Betta fish make bubbles?

A bubble nest is the first step in the reproduction process.

Male Bettas build nests by blowing bubble clusters that act as a haven for eggs and fry.

If your Betta is building a bubble nest, it is a good indication that he is happy and healthy.

What is a Betta Bubble Nest?

Have you ever spotted a bunch of bubbles sitting at the surface of your tank?

This is a bubble nest.

There is a handful of fish species that make bubble nests and Bettas are one of them.

These nests can be made up of tiny bubbles that resemble soap foam or larger more distinct bubbles.

Some may be concentrated in a specific spot with a small surface area and others could be a thin layer of bubbles that covers a larger surface area.

Your fish may even change the way his nests look over time.

What are Betta Bubble Nests For?

Bubble nests are built purposely by male Betta fish for either breeding purposes or just because he is happy and content.

This action is rarely performed by a female Betta.

These nests act as a shelter for Betta fish eggs and newly hatched young.

Baby Betta fish are not good swimmers when first born so having a safe space to hide is imperative to their survival.

A bubblenest from a Betta fighter fish containing many baby Betta fry

Does a Female Need to be Present For My Betta to Make a Nest?

Male Betta fish can build nests even when no female is present.

It is a natural urge for your Betta to reproduce, hence why he will feel the need to build a bubble nest.

He will also make a nest if he is happy and his tank conditions are perfect for him.

How are Bubble Nests Built?

Depending on how long you have owned your Betta, you may have spotted him popping up to the surface of your tank and taking a gulp of air.

This is normal behavior for Bettas.

They have an organ called the labyrinth that allows them to take oxygen from the air instead of always processing it through their gills.

This organ allows male Betta fish to build bubble nests.

Building these bubble nests is not a particularly complicated process.

They are built by blowing saliva-coated bubbles of oxygen that sit on the surface of your tank.

Coating the bubbles in saliva strengthens the nest and ensures that the bubbles will stick together.

These nests can vary in terms of size and depth.

Generally, the bigger the male the larger the nest.

Building these nests will often happen quite frantically and will generate a lot of noise.

How Often Are Bubble Nests Built?

No two Betta fish are the same so it is impossible to have any rules for how often they should be building bubble nests.

I have found some fish to build daily and others only sporadically.

Everything in between can be considered normal.

Some Bettas even changed their building pattern.

If your Betta isn’t building nests at all, don’t be overly concerned.

It isn’t uncommon for captive Bettas to not build bubble nests.

You may find that your Betta will slow down building nests after about 12 months of age.

This is because their prime breeding age is between 4 and 12 months.

How Do I Encourage My Betta to Build a Bubble Nest?

Building a bubble nest can be a frustrating experience for your Betta if your surface water conditions are not right.

There are a few ways you can help encourage your fish to build a bubble nest.

Keep in mind, that Betta fish lives in shallow slow-moving ponds in nature.

Even small splashes from your filter can disturb the fragile nests.

Try adding surface debris such as floating plants like hornwort or elodea.

This will add structure and protect the nest from any current in your tank.

Your Betta will be able to anchor his nest onto these plants and find it easier to maintain it.

Another thing to encourage bubble nest building is keeping your Betta in a large enough tank.

Betta fish needs at least a 5-gallon tank to be happy and mentally stimulated.

A rectangular-shaped tank is also better than a rounded tank as this will give your fish corners to build his nest against.

betta fish making a bubble nest

How Do I Clean My Tank With a Bubble Nest In It?

If you are not planning to breed your Betta, don’t worry about disturbing the nest while cleaning.

A clean tank is far more important than the bubble nest and your Betta will not be overly concerned about the nest being removed.

If you want to save the nest it is possible to gently scoop it out of the water while cleaning and place it back on the surface after the job is done.

Why Is My Betta Not Building A Nest?

As long as your Betta fish seems otherwise healthy, he may simply not want to mate.

There are however a handful of things to check through to ensure his environment is optimal.

1) Water temperature: The ideal temperature for your betta fish is 78°F and 82°F (25.5C to 26.5C).

2) Lack of stimulation: Some Betta fish will not feel the need to build unless a female is present and they feel that there is a real possibility of mating. If you are an amateur fish keeper, you shouldn’t add a female directly into the tank. Keep the fish separated by a clear barrier without them being able to make direct contact.

3) Water conditions: Despite Betta fish being able to live in dirty water in the wild, a dirty tank is detrimental to their health. Ensure all your water levels are balanced and your tank is kept clean.

4) Lack of Decor: Bettas like to build their nests attached to objects at surface level. If your tank is void of any decor or plants and is bare he may not feel the urge to nest.

5) Age: As mentioned before, a Betta’s prime age for breeding is between 4 and 12 months. If your fish is getting on in years he may not feel the need to build a nest.


When you first catch your Betta blowing bubbles, it may come as a surprise.

But this is a good sign that your Betta is in good health and is happy with the conditions he is living in.

Take it as a sign that you are being a good fish parent!

On the other hand, if your Betta is unable to make any bubble nests, do not stress too much about it.

As long as you follow the tips above and make sure he is healthy, you might just have a fish that doesn’t feel the need to mate.

If you are interested in knowing if you can put other fish with your Betta then have a look at – Can you put other fish with bettas?

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Irma Bense is the founder of BetterFishkeeping.com. She has over 42 years of experience in keeping fish.She has kept both freshwater and saltwater fish through the years.She has extensive knowledge in breeding numerous species of fish from Show Guppies, Cory Catfish, German Blue Rams to Apistogrammas.You can learn more about Irma on the 'About' page.

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