There are two main types of bubbles that bettas will blow. Male (and some female) bettas will blow bubble nests, which are huge blobs of bubbles that float on the top of the water. They may also blow small bubbles that pop quickly if the oxygen in the water is too low, or if there is ammonia or nitrite in the water.
Betta fish blow large bubble nests if they want to spawn. This behavior is primarily seen in male bettas, and all males will blow a bubble nest at some point in their life, though some females will do this as well. Bettas will also spend time at the top of the water drawing in atmospheric air, which could result in them blowing some small bubbles. This could be normal if they are simply using their labyrinth organ, but if the activity is excessive, the water quality may be poor.
In this article, we will cover bubble nests, breeding, disturbing the bubble nest, labyrinth organs, lack of oxygen, and surface film.
Bubble Nest
Most species of bettas are “bubble nesters”, which means they create a bubble nest and care for their eggs and young in there. The bubble nest is normally created by the male betta and is made of saliva and water.
While these bubbles will pop, they normally last several hours. The male constantly guards his nest, both while there are eggs in it and before spawning and keeping the nest in tip top condition is essential for his chance at breeding.
Bettas in captivity that have never seen females will still create bubble nests. They have a natural instinct to breed and pass on their genes, so they will start by making bubble nests. While people often say that only happy bettas make bubble nests, this is untrue.
Any betta will make a bubble nest, even ones being kept in tiny containers that don’t have a filter and are full of ammonia. It’s simply an instinct.
The bubble nests are used to hold the eggs and young fry. Once the fry
Once all the fry start reaching the wiggler stage and can swim close distances, the poor male doesn’t get a break. Since they can have nearly 300
The little fry will attempt to swim away from him, for seemingly no reason, since they run out of steam a few inches from the nest and fall to the bottom. If the male doesn’t see them, they die.
Breeding
Since bubble nests are vital to taking care of the fry, you cannot successfully breed bettas without a bubble nest is present. If you attempt to introduce the male to the female before a bubble nest is built, they will simply become aggressive.
The male tends to get frustrated that the female refuses to breed, and the female gets frustrated that the male hasn’t built a bubble nest. Normally the male gets too upset to even think about building a bubble nest once the female is in the tank, so you will have to separate and try again.
In order to properly spawn them, the male should be placed in the breeding tank for 3-4 days before the female is introduced. If the male hasn’t built a bubble nest at the
This allows them to see each other and interact, without the possibility of them fighting. You should only introduce them for a few hours, as leaving the female in the vase too long is damaging.
The purpose of the vase being tall is just so it can
Once the female shows submissive behavior and the male has built a bubble nest, you can release the female into the tank to let them spawn.
Disturbing the Bubble Nest
Now, since bettas need the bubble nest to breed, they tend to be very protective of them. If the bubble nest is damaged or otherwise not up to snuff, females will refuse to breed with them. Therefore, they defend the nest, even without any babies in it.

Why does this apply to you? Well, cleaning the tank with a bubble nest in it can become an issue. During water changes, the water level drops, and the bubbles often get stuck to the side of the tank and pop.
This can make your little buddy very angry, and he may try to attack the siphon or your hand. If you ruin the bubble nest, you won’t send your betta into depression, though he may be a bit angry for a while. It doesn’t cause any lasting damage to them, since they aren’t currently breeding, and they can just make a new one.
If you don’t disturb it, the male will eventually tire of maintaining it and it will pop on its own. Either way, the bubble nest will disappear for a few weeks before the male feels like making another one.
Labyrinth Organs
Betta fish have both gills and a labyrinth organ. The labyrinth organ is similar to lungs and bettas use this organ to extract oxygen from the atmosphere. Bettas need to have access to the air in order to use their organ and get enough oxygen.
This organ evolved because bettas come from very warm areas of the world and slow-moving streams. Warm water cannot carry as many nutrients or as much oxygen as cold water. Slow moving water also tends to have a very low amount of dissolved oxygen.
Since their natural environment makes it difficult for fish with only gills to live in, the bettas have an extra organ so that they can thrive. This organ is still useful in captivity, as filters for bettas tend to have a low flow, which lessens the amount of dissolved oxygen in the water.
Since they have to use these labyrinth organs in captivity as well, they go to the surface and take gulps of air. This is normal behavior and not something to be concerned about. However, in low flow environments, it can make little bubbles on the surface of the water.
Lack of Oxygen
If your tank has low dissolved oxygen levels, then your betta will gasp at the surface much more frequently than it should. While they can survive the environments well, there may also be some ammonia or nitrite in the tank, which can kill them.
There are not many tests available to determine whether or not your tank has a low dissolved oxygen content, but there are many tests available to rule out ammonia and nitrite poisoning.
Ammonia burns fish and causes damage to the gills, and the damaged gills can throw symptoms that look like oxygen deprivation. In fact, it is oxygen deprivation, as the burns prevent the gills from functioning properly, but increasing aeration won’t solve the whole problem.
Nitrite prevents hemoglobin in the blood from carrying oxygen and suffocates fish. Methylene Blue is a medication that can help reverse the effects of nitrite poisoning. However, it will stain everything in the tank and kill the beneficial bacteria that keep your nitrogen cycle going. It is best to move your fish to another heated container with Methylene Blue for several days.
The best way to help a fish suffering from ammonia and nitrite poisoning is to do large water changes, 50-80% per day for several days. At least for every other day for a week. For low dissolved oxygen, add a bubbler to increase surface agitation and gas exchange.
Surface Film
Protein film on the surface of the water is common in low flow tanks. However, this film holds bubbles better than plain water, so little bubbles from your betta breathing will stick around. This film can make it more difficult for them to breathe, so you should increase aeration and surface agitation to get rid of it.
In conclusion, betta fish blow specialized bubbles to create bubble nests. They can also make small bubbles when breathing using their labyrinth organ. There is no way to stop betta from making bubble nests, but frequent water changes will resolve other issues.