7 Reasons Your Betta Fins Are Curling (& What To Do)

Last Updated on 2023-12-19

Male betta fish have long, flowing fins that are a sight to behold. But when they start curling, it can be a cause for concern. Fins curling can be due to various reasons, and fin rot is not always the culprit.

In this article, we’ll discuss the reasons and problems related to your betta fish fins curling and help you overcome this complication. So, keep reading!

Key Takeaways:

  • Betta fish fins can curl due to various reasons, not always indicating a serious issue, but potentially highlighting underlying problems.
  • Reasons for betta fins curling include genetic anomalies, injuries from aggression or territorial fights, old age, anxiety, incorrect water temperature, poor water conditions, swimming against strong currents, among others.
  • Treatments for curled betta fins involve checking and adjusting water parameters, providing more hiding places, removing aggressive tank mates, maintaining proper diet and nutrition, addressing potential illnesses, reducing noise and avoiding reflections.
  • Betta fin rot is distinct from fins curling and is caused by bacterial or fungal pathogens, leading to identifiable symptoms such as jagged or ragged fin edges, deterioration, inflammation, color fading, and loss of appetite.

Why Are My Betta’s Fins Curling?

Betta fins curling is not always a serious issue, but sometimes it can indicate that there is a bigger problem you need to address immediately. As discussed above, Betta fins curl due to various reasons, which we will now tell you about, so you don’t have to go through this mix-up.

Reasons for Betta Fins CurlingDescription
Genetic AnomaliesBetta fins may curl due to inherent genetic abnormalities, observable from the fish’s birth and becoming evident as it matures.
InjuryAggressive behavior in betta fish, especially among males, can lead to territorial fights causing injuries and damage to their fins.
Old AgeAs betta fish age, their fins may naturally curl, twirl, and wear thin over time, signifying the impact of aging on their fins.
AnxietyStress and anxiety in betta fish can manifest as curled fins, along with other signs like slow movement and lethargy.
Incorrect Water TemperatureExtreme water temperatures, either too high or too low, can result in betta fins curling up, impacting their health.
Water ConditionsHigh levels of ammonia in the water can lead to the curling of betta fish fins, emphasizing the need for regular water checks.
Swimming Against A CurrentStress caused by having to swim against strong currents can result in betta fish fins curling, necessitating adjustments to the tank’s filter flow rate.

1. Genetic Anomalies

Genetic abnormality is one of the key factors for betta fins curling. This problem is present since the fish is born and only becomes visible when the betta has matured. So, you should always observe the signs from the very start.

2. Injury

Since betta fish are naturally aggressive in nature, especially males, injuries are bound to happen. Male bettas are territorial, so fights might occur in the fish tank leading to the fins getting damaged.

3. Old Age

Another reason for fins curling can simply be old age as the fins curl up, twirl, and wear thin over time. Bettas normally live for 2-4 years, but if you take proper care of them, a betta fish can live up to 10 years. Every living thing deteriorates, and so does a betta fish.

4. Anxiety

Betta fish are also living creatures just like us human beings, and we all feel anxiety at some point in our life, and so does the fish. Curled-up fins are an indication that betta fish is in a state of distress. Other signs of anxiety include slow movement and lethargy.

5. Incorrect Water Temperature

Water temperature plays a significant role in the curling of the fins. If the water temperature is too high or too low, it may lead to the betta’s fins curling up. The optimal temperature range for a betta fish is 78-82 Fahrenheit or 26-28 degrees Celsius.

6. Water Conditions

If the water contains a high level of ammonia, the fins of the betta fish will probably curl up. In order to avoid this, you must perform regular water checks so this problem may not arise.

7. Swimming Against A Current

This is a rare occurrence, but it is also possible. If your pet fish has to swim against strong currents, it can quickly stress it out and result in the fins curling. A quick solution is to decrease the flow rate of your tank’s filter.

betta fins curling

How Do You Treat Curled Betta Fins

Fortunately for us, we can treat the curled fins in most cases. Let’s discuss the various steps which can help in the treatment or prevention of the curls.

1. Check The Water Parameters

One of the mistakes people make is they forget to test the water parameters in the tank. This will help in seeing if the parameters have changed. If the temperature, ammonia, or pH are higher or lower than usual, you must do everything to revert to the latter.

2. Add More Hiding Places

We know that stress/anxiety can result in the curling of the fins, and the betta fish might be stressed out because of another fish in the tank. So, you must add more hiding places for your fish. Plants and caves are ideal places where your beta will see other fish and be more relaxed.

3. Remove Bullies

If your betta fish is being bullied by other fish in the tank and, as a result is getting injured, it can make their fins curl out of fear or trauma. This can happen when there are more aggressive breeds sharing the same aquarium. You must remove the perpetrator or provide the betta fish its own safe place where it is secure and out of harm.

4. Diet And Nutrition

If your betta has curled-up fins, it may be due to less feeding, so keep feeding it to can maintain its strength. The addition of pellets in small amounts, like one or two, can bring a positive change in the recovery. Also, make sure to provide it with nutritious fish food to help it recover.

5. Treat Any illness

If you suspect your betta is ill, you should do everything possible to treat it. Try various approaches like changing the water, secluding them, checking hygiene, and so on.

6. Reduce Noise Around The Tank

Noise can sometimes cause your betta fish to get stressed out. The water vibrations due to the noise might scare them, so less noise is usually recommended.

7. Avoid Reflections

It is important to make sure that your betta fish does not catch its own reflection in its water tank. If this happens, the fish is likely to start flaring at it, which can stress out the fish even further.

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What Does Betta Fin Rot Look Like?

Betta fin rot, for sure, is not something pleasant to look at. But you do not need to panic immediately. It is essential to know how to spot the disease before it’s too late.

The edges of your betta fish’s fins will look worn out, and their color may change from black to red. The signs of betta fish fin rot also depend on the severity of the rot.

These are the main signs which indicate that your betta fish’s fins are rotting:

1. Jagged Fin Edges

Brown, jagged fin edges with white spots on the fins are normally observed in mild cases. The white spots are observed during the first stage and are difficult to catch due to their small size.

2. Ragged Fins

Another sign of fin rot can be ragged fins. This could be due to various reasons, like some other fish bit the tail, or your betta fish got damaged by the ornaments inside the tank, or maybe the betta fish nibbled its own tail.

3. Deterioration Of Fins

For an average amount of fin rot, you will see that the fins start deteriorating and slowly fade away. These fins may be gaping/shedding blood and develop frizzy growth on the tips.

4. Inflammation And Redness

Inflammation and redness can be seen at the base of the fin in severe cases. This indicates infection and can spread through the whole body of the fish. Inflammation will also make your fish inactive and slow and develop swimming issues or other diseases.

5. Fading Of Color

This is a major sign for indicating whether your betta fish’s fins are rotting or not. If you have a vibrant betta fish, then you will be able to identify easily if the color is fading or not.

6. Deterioration Of Tail

You might notice that your betta fish’s tail is clearly getting worse and showing signs of rot as well. Plus, color changes can also be seen in the tail. Observe the tail area closely if you suspect something.

7. Loss Of Appetite And Lack Of Movement

If your fish is not eating well, completely refusing to eat, and you notice that it is behaving oddly or is behaving unusually lethargic- it can be an early sign of fin rot. However, this will usually be accompanied by the other visual symptoms we’ve mentioned.

Check out this video by Your Fish Guide on other reasons why your Betta fish’s fins are curling!


What Are Clamped Fins?

This is when a fish continuously holds its fins bent against the body in an aquarium; the fins of the fish are not extended, and the fish is lethargic. Clamped fins are not a disease but an indication that something else is wrong or happening to your fish.

Determining the reason for the problem is important to find a cure; however, it is usually recommended to add 1 tablespoon of aquarium salt (per gallon) to prevent fin clamping.

How is Betta fins Curling Different From Fin Rot?

Betta fins curling has to do with old age and genetic disorders; however, fins can curl due to injury, water temperature, and so on, as discussed above. Fin Rot, on the other hand, is a disease caused by bacteria or fungal pathogens. This condition is different than curled fins and requires immediate attention and treatment.

Why are my Betta Fish Fins Shriveled?

Shriveled Betta fish fins may result from poor water quality, injuries, infections, aging, or stress. Maintain clean water, reduce stress, and promptly address health issues for improvement. Seek vet or fish expert advice for persistent problems.


Now you know how to differentiate between fin curling and fin rotting, as the latter is a disease. If you’re uncertain, it’s always best to consult an aquatic veterinarian. We hope this article was helpful and informative to you.

In short, there can be many factors that can cause your betta fish fins to curl up. The most common factors include bad quality of water, old age, genetic disorder, or the wrong water temperature.


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