Why are my betta fish fins deteriorating?

In this blog post, we will discuss the reason why betta fish fins can deteriorate. We will also talk about ways to fix this problem.


In this blog

  • Why are my betta fish fins deteriorating?
  • What are the signs that betta fish fins are deteriorating?
  • What are some of the reasons why betta fish fins may start to deteriorate?
  • How do you treat fish fins that have deteriorated?
  • How can you keep betta fish healthy and free from fin deterioration?
  • Summary 
  • Frequently asked questions
  • Reference

Why are my betta fish fins deteriorating?

If your betta’s fins or tails look frayed, torn, or deteriorated, it may be a sign of fin rot. Fin rot is a common problem in betta fish, and it can be easily seen since their fins are very long and flowing like a veil.

There’s a risk that if you don’t take steps to treat fin rot, it can get worse and more troublesome over time. We will discuss fin rot in detail in the next sections of this blog.

What are the signs that betta fish fins are deteriorating?

The signs of betta fish fin rot can be understood in stages, with the most common symptoms beginning with a decrease in the number of fins. 

If you’re wondering if your fish fin rot is at what stage, remember that in stage one they start to lose color around the edges of the fins.  Its fin color can become either white, red, black, or brown.

In the second stage of fin rot, the fish’s fin edges start to look uneven or ragged because the affected areas are sure to die and fall off.

In the third stage of fin rot, the fins deteriorate and the infection will spread to the body, which could ultimately lead to the death of the betta fish.

Other most common symptoms include: 

  • Loss of appetite, because the fish’s body is more focused on fighting the infection, leading to decreased appetite.
  • Lethargy/ tiredness.
  • Lesion development in the fins of betta fish.
  • The fish may become unable to swim as the fin rot progresses.

What are some of the reasons why betta fish fins may start to deteriorate?

In this section, we will discuss the reasons why betta fish fins may start to deteriorate.

Damage or wound to betta fish may deteriorate their fins

Bettas like their aquarium decorated as it wards off boredom, but if the decorations are sharp and pointy, it can damage their long, flowing pectoral fins.

If you ignore damaged betta fish fins, they will slowly deteriorate, leaving fish susceptible to fin rot and affecting their swimming abilities.

An overcrowded betta fish tank may deteriorate their fins

If you put a lot of fish in a small tank with a betta fish, your fish will become infected with fin rot due to the lack of space in the tank.

Tanks with a high number of occupants can lead to a higher number of infections.

An inadequate betta fish diet may deteriorate their fins

Betta fish are primarily carnivorous and need a lot of protein in their diet to survive. They need vitamins, fats, and other minerals in a balanced amount to stay healthy and free of diseases and infections. 

If any of these are missing, they will become susceptible to many infections such as fin rot or fin deterioration. Feed them proteins, vitamins, fats, and other nutrients in appropriate or balanced amounts to avoid infection.

Fight with aggressive tank mate may deteriorate betta fish fins

The betta fish, also known as the Siamese fighting fish, is known for its fighting nature and prefers to stay alone in an aquarium due to its aggressive nature. 

If you keep them with incompatible or aggressive tankmates, they may end up fighting each other and this will damage their long, lowing pectoral fins. 

The situation gets worse when two male betta fish are kept together, as they are prone to fighting each other to death. Avoid keeping male betta fish together in the tank.

Avoid fin nippers as they can become attracted to your betta fish’s long and flowing fins, and may try to nip them.

Poor water quality may deteriorate betta fish fins

Betta fish are very sensitive to poor water conditions and if ammonia or nitrate levels rise in an aquarium, they may feel uncomfortable in the aquarium and their fins begin to deteriorate due to poor water conditions.

It is important to keep water conditions in a betta fish tank pristine to ensure their health.

How do you treat fish fins that have deteriorated?

Are the conditions in your fish’s environment safe? Is there something in the water that is causing them problems? 

Is the environment your betta fish lives in causing the fins to deteriorate? Find out the source of the problem and take steps to address it.

Move injured betta fish to a hospital or quarantine tank

Move infected betta fish to another aquarium or hospital aquarium to prevent the spread of infection to other fish.

The fin deterioration can also be caused by bacterial or fungal infections, so you can use a broad-spectrum antibiotic called maracyn or antifungal medication to help treat the problem.

There are other treatments available that don’t harm the plants and beneficial bacteria in the tank while treating betta fish for fin deterioration.

Perform water changes in betta fish tank

The main cause of fin deterioration in betta fish is dirty water.Put a reminder in your phone or calendar to perform water changes and tank cleaning on a weekly basis.

Make sure to change the water carefully, because if you do water changes without acclimating your fish, they may die after water changes.

Indication of recovery in betta fish:

It will take a few days to recover from deteriorating fins. There are several indications that a betta fish is recovering from fin deterioration or fin rot.

  • The betta fish appear to be healthy and without any new symptoms.
  • The energy levels of betta fish are back to normal.
  • The betta fish will start eating again like before.
  • The fins on your deteriorated fish start to grow back.

How can you keep betta fish healthy and free from fin deterioration?

To keep betta fish healthy and free from fin deterioration, we must do the following:

Monitor betta fish water every day 

To avoid fin deterioration and other infection, make sure to monitor betta fish water regularly using a water testing kit to keep the levels of organic pollutants like ammonia and nitrate in check.

Ideal water parameters for betta fish :

Organic pollutants :

  • Ammonia levels – Zero ppm
  • Nitrate levels  < 20  ppm
  • Nitrite levels – Zero ppm

Water temperature 

  • 76-81F

Water pH

  • 7 – almost neutral

Remove uneaten food every day from betta fish tank

Leftover food can change the water chemistry and make it unsuitable for betta fish to live in. It is important to remove uneaten or leftovers from the tank regularly, as this will help to keep the water clean and free of harmful ammonia levels.

Avoid overfeeding your betta fish

Overfeeding is one of the main reasons for the poor water quality, as overfeeding leads to more pooping and this leads to more ammonia levels in the tank. 

Ammonia spikes in the tank can lead to poor water chemistry and make it difficult for fish to survive. Betta fish need a certain amount of food to stay healthy, so don’t overfeed them. 

Check betta fish food labels before feeding them

  • Never feed your betta fish expired food products, always check food labels before giving your betta fish food.
  • Feed your betta fish high quality food products and never compromise on the quality of the food.

Avoid decorating betta fish tank with pointed accessories

To keep your betta fish safe and healthy, remove any sharp or pointy decorative accessories from their tank and replace them with smooth, non-harmful accessories.

Add silk plants to your betta fish tank to make them more comfortable and provide them with a place to hide and rest, instead of adding fake plants that are sharp and pointy.

Keep betta fish in bigger and spacious tanks

To avoid problems with fin rot or fin deterioration, it is best to keep your betta fish with tank mates in larger, spacious tanks, rather than in a small, compact tank.

  • If you plan to keep betta fish in a community tank, a 10 gallon or 20 gallon tank is better. 
  • If you want to house a betta fish with other fish, you should choose a tank that has a capacity of at least 10 gallons.


We learned why betta fish fins deteriorate, what the symptoms are, the treatment, and talked about everything related to it.

To sum it up again:

  • Keep the betta fish tank clean.
  • Monitor the betta fish water parameters regularly
  • Keep betta fish with other fish in a bigger and spacious tank.
  • Avoid overfeeding and expired food to betta fish.
  • Remove leftovers every day from the substrate.
  • Don’t keep sharp decorative items in a betta fish tank.
  • Keep the water clean.

Frequently asked questions

Can you feed expired food to your betta fish?

Never give your betta fish food that has expired. Always check the labels before feeding your fish. Expired food is not good for betta fish health.

Can you keep finnippers in a betta fish tank?

Avoid adding finnippers in a betta fish tank because they can damage their beautiful, long and flowing fins.

Can you keep betta fish with tank mates in a five gallons tank?

You should never keep betta fish in a tank with other fish below ten gallons in size. Tanks that are too small or too crowded can lead to a lot of infections.

Is it important to remove leftovers from the betta fish tank?

It is very important to remove any leftover food from a betta fish tank, as this can change the water chemistry and make it unsuitable for betta fish to live in.

Are betta fish prone to becoming lethargic as a result of fin deterioration issues?

Betta fish can become lethargic as their fins deteriorate.

Can a betta recover from fin deterioration?

Betta fish can recover from fin deterioration by getting treatment as soon as it happens and taking care of their tank conditions.