What is a Bubblenest?
One day you wake up and see a grouping of tiny bubbles at the surface of the water in your betta’s tank. It may be along the tank wall, right in the middle, on the edge of a plant leaf, or another special place in your betta’s tank. What are all of these little clear bubbles you may wonder?

This huge bubblenest was blown by the betta Ermac. (Photo taken by Mike).

The purpose of a bubblenest
While it’s just fun for us to observe our betta building and tending to his bubblenest, the nest itself actually serves a very important purpose in the spawning process between male and female. A male betta builds a bubblenest as a means of attracting a female to mate. Once the nest and male gets the approval of a female and a spawn occurs, the male will place and tend to the fertilized eggs in the nest where they will later hatch.

The building of a bubblenest
If you’re lucky enough to catch your betta blowing bubbles for his nest, which usually takes place in the dark at night, it’s quite the interesting procedure. The male will take in air at the surface, then swim to the area beneath where the nest is being made and release a small bubble or two. The betta will continue this method back and forth until a nest of many bubbles is formed as they build up beneath each other. The actual bubbles are produced with mucous and you will notice they stick well to each other and any surrounding surfaces, which serves as a means to keeping eggs safe in the nest.

Maintaining the bubblenest
Some males will be very determined to maintain their bubblenest every day, while others may lose interest a day or two after the initial building of the nest. Changes in water chemistry can trigger males to build bubblenests, so it’s not uncommon for your betta to make one after a water change or if you’ve just recently brought him home. Don’t worry about removing the bubblenest from the tank during water changes, as the betta is likely to make many more in his time with you.

In nature, it is common for fish to breed around the time of storms when there is a drop in barometric pressure, causing a change in relative water pressure. Therefore due to their instincts, your bettas can often serve as a good predictor of the weather to come in the near future. If you’re expecting a rain or snow storm in a day or two, it’s likely that your betta will greet this with a nice bubblenest.

What if my betta doesn’t blow a bubblenest?
While it can be said that a male blowing a bubblenest on a regular basis is a sign of good health, this is not necessarily the case. Sometimes a sick betta will still blow bubblenests, while a perfectly healthy betta may not. There may be something causing your betta to not blow a bubblenest – are the water conditions less than ideal, is there curent in your tank from a filter, is the water being kept at the proper temperature? Sometimes even with all factors considered a healthy male betta just won’t build a bubblenest. It has also been reported from time to time that some female bettas blow bubblenests, although it is not as common.