Q: Anon wrote,
I have had my betta for almost 6 weeks now and he still hasn’t blown a bubble nest. He is in a 5 gal with a filter but the filter is set very low and it doesn’t create much current at all. My understanding is that males will blow bubble nests when they are healthy. Mine has good color, eats well and is pretty active. Why do you think he won’t blow a nest?
A: We sometimes associate bubble nests with good Betta health but it this is a generalization and alone isn’t concrete evidence of a healthy or unhealthy Betta. Many bubble nests are blown by healthier Bettas but not all healthy Bettas blow bubble nests. In addition to that, each Betta is different. Some males will blow nests on a daily or weekly basis. Some may only blow bubble nests every couple of months and some may only blow one or two in a year.
Your filter current, however slight, may discourage your fish from blowing the nest at all. This isn’t harmful in anyway, he just won’t blow the nest. I have one Betta, for example, living in a similar five gallon tank with a current so slight that you can’t even see it if you try. He will not blow any bubble nests in this tank at all, though I will observe a few scattered bubbles from time to time. If I put him in a breeding tank without a filter, or turn off the filter entirely, he quickly goes to work.
Remember, Bettas are blowing nests to prepare for fish fry but how they determine when to blow a nest isn’t really known. If he senses the condition aren’t right (ph, gh, etc) he may opt not to blow the nest. He may also need encouragement with lots of nutritious live or frozen foods or a little stimulation by observing a female Betta near him.
Unless you’re trying to breed him, the nest itself isn’t particularly important. The benefit of clean filtered water probably outweighs the need for the bubble nest. If after a few months you still really want to see a nest, try conditioning him with a new feeding regimen and introducing a female in an adjacent tank that he can observe.