Betta Flashing

Why Is My Betta Flashing?

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What does it mean when your betta fish “flashes?” Does that behavior mean your fishy friend is sick or is he simply clowning around in his tank?

In this guide, we answer those questions and more, including how to tell when flashing is a sign all is not well with your betta buddy (and a few betta fish care tips for treatment of whatever may be wrong).

What is flashing?

Flashing is the term that is commonly used to describe a fish’s rubbing or scratching against objects in the aquarium. Your betta, also called a Siamese fighting fish, may use decorations, plants, substrate, and even internal filter boxes as suitable scratching areas.

And in some cases, the betta will leap right out of the water so it can use the surface tension to scratch its skin. Bettas are natural jumpers, using that behavior in the wild environment to move between puddles during the dry seasons as they search for mates, food, or to escape another male betta.

Keeping that in mind, always make sure you have a lid or cover slide on your tank to keep your jumping betta safe.

Betta Fish Flashing

Why do betta fish flash?

Fish typically exhibit flashing behavior when they are either uncomfortable because of sickness or suffering from stress.

Water conditions

You may notice your betta fish begin flashing after you carried out a water change. That’s because sometimes the water change results in a higher concentration of metals like copper or iron in the new water.

The presence of these metals in the water (or poor water quality for other reasons) can irritate your fishy friend’s skin, causing the betta to rub itself on its tank in an attempt to alleviate its itchiness.


Flashing is commonly caused by parasites present on the fish’s skin. The betta flashes against solid structures in an attempt to remove the parasites and stop skin irritation the little critters caused.

A few common parasites include flukes, trichodina, Costia, Chilodonella, and Icthyobodo.

Some parasites are present in most fish tanks, however, others find their way into aquariums on new fish, plants, or inside bags of live food. For that reason, you should always quarantine new fish for at least 10 days, wash plants thoroughly in an antibacterial medication solution, and use frozen rather than live food.


Ich, also known as ick or white spot disease, is a very common condition that can affect both fresh and saltwater fish.

Ich is caused by a parasite called Ichthyophthirius multifiliis. Although these protozoan parasites are present in most fish tanks, they only become a problem when the fish are sick or stressed. A stressed-out fish has a weaker immune system, making it more vulnerable to attack by bacteria and parasites like ich.

The ich parasite has a complicated life cycle. The first sign of trouble for your betta is usually flashing. That occurs when the parasite has attacked the fish’s skin, causing itchiness and irritation that the betta tries to relieve by rubbing himself against objects in its environment.

As the infection progresses, the ich parasites can be seen as tiny white spots scattered in a rash across the betta’s body, fins, and gills. You might also see your betta gasping at the surface, clamping its fins, and refusing to eat.

In advanced cases that were left untreated, the sick fish’s gills can become completely clogged with parasites, leaving the fish unable to breathe. Eventually, it suffocates.

Treating ich

Luckily, if you’re one of the many fish owners who are vigilant and check on their fish frequently, you might spot it early on. And when detected early, ich is quite easy to treat. Raise the water temperature to 82 degrees Fahrenheit for three days to disrupt the parasite’s life cycle, and treat the tank with an over-the-counter white spot disease medication you can buy from your local fish or pet store.


Fluke is a catch-all name for several species of parasites that attack freshwater pond and aquarium-kept fish.

These parasites include fish lice, anchor worms, and flatworms. All these creatures can be seen with the naked eye attached to the fish’s skin and gills, and the presence of flukes causes intense irritation to the fish, causing it to flash against things in the tank to try to remove the parasites.

Most species of flukes can be dealt with by treating the water with an anti-parasitic medication that you can find at your local fish store or veterinarian’s office. It can also be helpful to add aquarium salt to your tank for a week or so, being careful to follow the manufacturer’s dosage instructions on the product’s packaging.

Poorly Cycled Aquarium

Sometimes, you’ll see fish flashing if their aquarium has not been fully cycled. In that case, the tank water will contain high levels of ammonia and possibly nitrites that can irritate the betta’s skin and sensitive gills.

Problems with cycling usually occur with brand-new tanks, often because the hobbyist is too keen to get the beautiful fish home and hasn’t waited long enough for the tank to cycle. However, a massive water change can also disrupt the delicate balance of the aquarium environment.

The biological media in your filtration system is there to provide a home for beneficial bacteria. Those bacteria process the ammonia that’s produced by decomposing organic matter in the aquarium. If the bacterial colonies are not established in the filter media, the water will contain high levels of toxic ammonia and nitrites that can be fatal to fish.

In new tanks, the nitrogen cycle can take 10 days to six weeks to complete. Conduct a water quality analysis every day or two with an aquarium water test kit to make sure ammonia and nitrite levels are zero before adding your beloved fish to the aquarium.

Fluctuating water temperature and pH levels

Some fish are highly sensitive to changing water temperatures and pH levels. Rapid fluctuations in water parameters can cause high levels of stress for your fish, which can often result in erratic behavior, including flashing. To prevent these problems, remember to test your tank’s pH level regularly and fit an accurate aquarium thermometer.

When is flashing normal?

If you see your betta fish flashing and everything else about its behavior is normal, there’s probably no immediate cause for concern.

In some cases, a betta’s flashing occurs for the same reason a betta fish flare might: just because. As long as your pet is eating properly, isn’t hanging at the water surface, and doesn’t have any obvious white spots or parasites on its skin, flashing is nothing to worry about.

If you haven’t introduced any new plants or fish to the tank within the past three months, the water parameters are within the correct and safe range, and you are feeding your betta a high-quality and balanced diet, you shouldn’t be too concerned if your fish flashes occasionally.

Sometimes, healthy bettas can carry a low level of parasites that they can deal with on their own. Just keep an eye on your betta and watch out for any other symptoms it might develop.

Is flashing dangerous for your betta fish?

If your tank is decorated with lots of rockwork and stones, it’s possible your betta could injure itself simply from flashing too much.

Fish that flash constantly and erratically can be susceptible to head and body trauma and damage to their scales. That can lead to secondary bacterial infection, which can exacerbate their flashing behavior, creating a vicious cycle.

Bettas with long, trailing finnage can be vulnerable to injury in aquariums containing sharp or rough objects, so it may be safer to substitute those items for plants and smooth stones or just remove the decorations altogether.

How can you prevent your betta fish from flashing?

To keep your betta fish safe from parasite attack, be sure to quarantine all new fish for at least 10 days before adding them to your tank. During that time, observe the fish for signs of sickness and treat accordingly. Once you’re sure the fish is healthy, you can add it to your main tank.

Quarantine isolates any sick fish, effectively preventing viruses, bacteria, and parasites from getting into a healthy aquarium. If you buy plants that have been kept with fish, it’s a good idea to quarantine the plants separately or wash them in a solution of antibacterial medication to kill anything sinister that might be lurking there.

Betta flashing while leaning on wall

In conclusion

Betta fish usually flash to relieve skin irritation that’s usually caused by parasites. Poor water quality or incorrect tank temperature can also be responsible for flashing.

Watch your pet closely for other symptoms that could tell you why your betta is flashing, and treat the fish accordingly with suitable medication. If a disease or parasite outbreak is not the problem, adjust the tank temperature or focus on improving the water quality.

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