Betta Fish Bubble Nests: Everything You Need to Know

You wake up one morning and go to feed your Betta buddy only to notice there are lots of bubbles on the surface of his tank. 

At first, you may think it’s a by-product of your filter. You give it a jiggle but all seems well with it. What could be causing this blanket of bubbles?

The most likely cause is that your male Betta fish has been busy constructing a bubble nest.

What’s a bubble nest?

Read on for some useful information on Betta fish bubble nests – it’s everything you need to know.

bubble nest


What is a Bubble Nest?

Several species of fish, some eels, and even certain types of frogs construct bubble nests (also called, foam nests). The bubble nest is exactly what it sounds like – a nest made from bubbles. 

Although not designed like a traditional bird’s nest would be, the Betta bubble nest is constructed under floating leaves or debris. If this is not available inside the habitat, the Betta will usually choose the corner of the tank with the least amount of turbulence. 

To create a bubble nest, the male Betta fish will blow a series of bubbles at the surface of the tank that is bonded together with saliva to give the nest durability and strength. 

Interestingly enough, you may hear your Betta making his nest. It can be quite loud when done at a frantic pace. 

When and Why Do Bettas Build a Bubble Nest?

Happy Bettas and those that are ready to spawn will build a bubble nest. In the wild, the Siamese Fighting Fish live in poorly oxygenated, shallow, and muddy waters. A bubble nest helps keep the eggs and newborn fry safe from predators and poor water conditions.

Not all bubble nests are created equally. Some male Bettas blow very tiny bubbles that appear more as foam on the surface of the tank, while others make big bubbles and thick nests that can reach up to 1 inch. 

Some experts think the age of the Betta may also play a role in the type of bubble nest that is produced. 

Spawning and the Bubble Nest

In many species, selecting a mate is based on the brightness of colors or the strongest fighter. However, in the Betta fish, the construction of the bubble nest could be a deal-breaker. 

Male Siamese Fighting Fish are solely responsible for building the bubble nest and caring for the eggs and fry. If the female deems his handy work as inferior, she will swim away and refuse to release her eggs. Some more “cheeky” females will even destroy the nest, forcing the male to start again.

If the female deems the bubble nest worthy then she will engage the male in the mating dance – this involves a lot of swimming and flaring of the fins. Once the “courtship” is finished the female will allow the male to flip her over and wrap his body around hers. He will then squeeze her to help release the eggs. 

The male will then go into “daddy mode” scooping up the eggs and carefully placing them into the bubble nest. If any eggs fall out, he will immediately retrieve them and place them back into the bubble nest.

As the eggs incubate for a few days in the safety of the nest, the male Betta is ever vigilant to guard and protect his young.

When the fry hatch, they can survive on their own, so it’s best to remove Dad in case he decides to snack on them. 

Once the male Betta has successfully “raised” the fry, he may begin to construct another bubble nest. Since there is no set time for spawning in an aquarium environment, happy and healthy Betta males can indulge in bubble nest making several times throughout their lifetime. 

How to Promote Bubble Nest Production

Not all Betta males build bubble nests all the time. Yes, they will indulge in this behavior when they are happy and healthy and in the breeding season but that’s not the only time. Some male Bettas will begin to construct a bubble nest at the very presence of a female betta in the tank. Whether she is mature enough or interested in breeding is not important to the male at this time.

If you want to promote the building of bubble nests, there are some things you can do to increase his productivity.

Water Temperature

The Betta is a tropical fish so if your tank is unheated it will affect his ability to spawn. The optimal temperature for the Betta species is between 75 and 80 degrees Fahrenheit. Increasing the temperature of your tank may increase his willingness to build a bubble nest.

Floating Plants

If you want to help your Betta with his bubble nest adventures, add some floating plants to his environment. Experts recommend Duckweed as it is easy to care for and will absorb excess nutrients from the water. It also provides the perfect shelter for bubble nests.

Adequate Space

Betta fish may not feel the need to build a nest in a small tank. Enclosures that do not provide adequate space are not conducive to finding a good spot to build the bubble nest (away from the heater or the turbulence of a filter) or for raising the fry. If you want to increase your Betta’s bubble nest construction, place him in a larger tank.

Tank Shape

Concave and half-moon-shaped aquariums are not the best for Betta fish as these tanks obscure the fish’s vision which tends to stress them out – a stressed Betta will not make a bubble nest!

Decrease Polluted Water

Even though the Betta species do live in murky, muddy waters in the wild, a polluted aquarium will decrease the likelihood of bubble nest production. Be sure to do weekly partial water changes and keep your filter running at maximum efficiency for the health and well-being of your Betta fish. 


Just like you would not want to live in a space devoid of furniture or decorations, neither does your Betta fish. Make his home inviting and fun to live in with decorations designed for Betta like Betta caves, plenty of live plants, and other suitable aquarium accouterments. To increase your Betta’s bubble-nest-making needs, add a clean floating lid (such as from a Pringles can). This simple object may be enough to encourage Betta’s willingness to build a nest.

The Right pH Level

Betta like a pH of around 6.8 and 7.5. Too high or too low will not only decrease his need to build a bubble nest, but it can be detrimental to his overall health and well-being. To ensure his tank is optimal, grab some test sticks and make a habit of checking the pH levels. 

Betta Fish Bubble Nest Conclusion

Having a Betta fish is a wonderful experience, especially when he is happy and healthy and building a bubble nest. 

If your Betta hasn’t built a bubble nest (and your tank is large enough and of the right shape) check your water parameters (temperature and pH). You may also want to add some floating plants, and decorations to help encourage this behavior. 

If your Betta still does not show any interest in bubble nest making, keep an eye on him for any health issues that may be brewing. If he is healthy and eating, he may just not be old enough to indulge in the act. Give him time and keep his tank optimal to help increase the chances of witnessing this awe-inspiring behavior.