What is Betta Fish Flaring?

Flaring is when a betta fish stretches out all of his gills and fins, making the fish looks significantly larger than it actually is. This is used to intimidate other Bettas that they perceive as a threat to their territory.

Why do Betta Fish Flare?

Betta fish flare as a sign of aggression. They could be defending their territory, attempting to attract a mate, or simply stretching.

One of the other names for bettas is the “Siamese fighting fish”. This name is well deserved. When two males encounter each other in the wild, they flare at each other until one backs down. If one doesn’t back down, they will fight – sometimes to the death. 

In the wild, this standoff rarely ends in death. There’s simply so much space for each betta that there’s no need to fight to defend their territory or their mate. One eventually backs down and retreats.

In an aquarium, there is no where for a fish to go to when it submits. So a fight is almost guaranteed. This is why two male bettas should never be kept in the same tank.

Should I Make My Betta Fish Flare?

Flaring is natural and healthy for a betta fish. Just don’t overdo it.

Once or twice a day for a minute or two is reasonable. Flaring helps to stretch out their muscles and keep them in shape. It’s important not to over do it when you first start training them to flare. Just like humans, they need to slowly build up their stamina.

When your betta does flare, you should take the opportunity to look at their fins and examine them for signs of tears and fin rot. Unhealthy fins are often one of the first signs of an unhealthy fish.

How Do I Make My Betta Fish Flare?

Bettas flare when they see other bettas. Rather than buying a second betta, just buy a mirror.

Hold it up to the tank and wait until your betta sees itself. You’ll know when it does because every fin will be stretched out.

The mirror that you use should be a small handheld mirror that does not stay in the tank. If the mirror is left in the tank, the bettas will see themselves and flare much more often than is healthy. A permanent mirror will lead to exhaustion, strain, and stress. This almost guarantees that your fish will end up sick.

Do Female Bettas Flare?

Yes, female bettas will flare at each other, just not nearly as often.

In general, females are much less aggressive than males so by default they flare less frequently than males.

As with most animals, this is largely dependent on the individual fish. Different fish have different personalities. Sometimes aggression is just a part of their individual personality.

Why Is My Betta Flaring So Much?

If you’re betta is flaring a lot, you really need to figure out why so you can stop it. Too much flaring is exhausting and unhealthy.

Bad Tank Mates

Which fish are with your betta? If it’s something with long flowing fins that your betta could mistake as another betta, you should try to rehouse one of the fish. Frequent offenders often include:

  • Other Bettas
  • Gouramis
  • Angelfish


Your betta isn’t smart enough to realize that it’s own reflection isn’t another betta coming to invade his territory. So look for possible surfaces that could cause reflections.

Are you near a window? If yes, then maybe you should try to move the tank.

Is there a mirror nearby? This is a bad idea in general. Move the mirror or the tank.

If there’s nothing obvious, maybe its the tank itself causing the reflection. If that’s the case, try to adjust the lighting. Turn it off and see if that stops the flaring.

If that fixes it, try repositioning the light and see if that fixes the aggression.