How to Treat Fin Rot in Fish ?

How to Treat Fin Rot in Fish? Causes, Symptoms, and Treatment

How to Treat Fin Rot in Fish?, Basically, fin rot is the most common condition affecting the majority of aquarium fish. Although it is not deadly in most cases, Sometimes it makes your fish sick to the limit of death. Every fish keeper sooner or later experiences this problem while keeping a fish as a pet.

Fin rot is relatively easily transmitted and can affect the rest of the aquarium life within no time. Although it spreads quickly, preventing this serious condition is also pretty straightforward and easy.

This article will discuss this disease, its causes, transmission, symptom, prevention, and methods to treat fin rot.

Let’s not ramble on anymore and get started with it.

What is fin rot, and what are its causes?

Many factors cause fin rot, and that’s why it is a pretty widespread fish disorder. Generally, in this condition, the fish suffers from full-body irritation, eroding various fish skin parts, especially fins and tail. Knowing the signs and symptoms of this condition is the key to its identification.

If this is left unattended, it might lead to the death of your fish. Most commonly, betta fish and goldfish are affected. But, other types of fish are equally susceptible to fin rot. Thus, understanding the signs and symptoms of this disorder is essential and getting immediate treatment is inevitable.


When it comes to the factors leading to fin rot, there is not just one to count. Thus its is important to notice your fish carefully and search for signs of any disease.


Basically, bacterias cause fin rot. Fungal and bacterial infections are commonly encountered. Following gram-negative bacteria are primarily responsible for fin rot. These agents cause ragged rotting of fin and tail. It also affects the delicate tissues of fish.

  • Vibrio
  • Pseudomonas
  • Aeromonas

The critical thing to understand is how these bacteria even ended up in your tank?

Many events are leading to the entry of these harmful bacteria into your tank. First and foremost is the use of old or untidy equipment and decorations. Most fishkeepers tend to use second-hand material in their tank; these things might be loaded with such harmful and infected agents.

Untidy Stuff in Aquarium

Furthermore, the rocks or other decorating stuff might be the reason for bacterial entry into the tank. Substrate, mainly gravel, might contain harmful bacteria and parasites. Apart from fin rot, these parasites might cause other diseases.

Unhealthy Food Items

Sometimes, the food items may also be infected with such bacteria leading to fin rot transmission to your tank. Thus, care is essential in this regard. Unhealthy food also puts unnecessary stress on fish.

Once bacteria reach the skin of your fish, it spreads like fire, causing sudden sickness of your fish, loss of strength. Thus, the fish feed should be carefully selected.

Improper Water Conditions

Another leading cause of fin rot is improper water conditions, frequent fluctuations in water parameters, and poor water quality. Coldwater, low pH, and inefficient water filtration system lead to fin rot. Thus, Using a good quality water filter is paramount.

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Frequent exposure to cold water decreases your fish’s immunity, making it prone to many more diseases. Thus, poor water quality is another contributing factor in spreading this disorder.


Overcrowding also leads to the fast transmission of infection. Moreover, the greater the crowd, the more the waste and more disease susceptibility. Tankmates should be selected carefully.

Additionally, water changes and overcrowding both induces stress, and stress is another significant factor leading to this condition. Aggressive tankmates can also aggravate the condition.

Thus, inflamed and stressed fish with poor feed is most prone to fin rot. All the above-stated factors play their part in causing and spreading fin rot.

Symptoms of fin rot

How can we possibly know that the fish is suffering from fin rot?

Well, there are quite many symptoms that appear while your fish suffers from fin rot. Fins and tail of fish are commonly affected, thus giving the name fin rot. Betta fish fins are frequently seen to be ragged.

Old and immunologically weak fishes are most prone to this deadly condition. Although, the symptoms of fin rot might get you confused with other related fish diseases. spot this; you need to remember the following points.

Restlessness and Agitation

 Firstly, your fish might feel restless and agitated due to the ongoing irritation on the body surface. Your fish might rub itself to the glass or other decorations in the tank to relieve this irritation. Fish may start nipping its fins.


Secondly, the most visible symptom is the change in coloration of fins. In the beginning, the edges of the fins turn greyish blue. This is followed by a change in color of the whole fin to dark blue. The discoloration is a classic sign of fin rot. Sometimes, this is also accompanied by red stripes or spots on the fins.

Spot Formation

Occasionally, white spots or lines are also seen in the fin rot. Mostly the spots are seen on the fins and tail of the fish.

This spot formation and discoloration is basically evident of damage or disturbance in the circulatory system.

Cloudiness of Eyes

Sometimes, cloudiness of the eyes is also seen and is a visible symptom of this condition.

You might notice the shortening of fins. It basically occurs due to the disintegration of fin tissue.

Ulcer Formation

Ulcer formation is the next stage. In fin rot, small sores or ulcers begin to appear on the surface of the fins. In the starting, these ulcers are only on the edges of the fins, but they usually spread fast if not healed at the spot.

Lastly, the ulcers proceed to the rest of the main body, causing extreme damage to your fish. At this stage, they are hard to treat, and your fish might die of it.

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Thus, as soon as you notice irritability and change in coloration, quickly move to treatment; otherwise, you might end up losing your fish.


Maintaining the health of the fish should be your utmost priority. Fin rot is hard to treat but pretty convenient to prevent. To protect your fish from this serious condition, you need to provide a clean and healthy living space free of any waste.

Following measures might prove beneficial for the health of your fish.

  1. Maintain appropriate water conditions and avoid frequent changes in water parameters to treat your fish.
  2. Avoid using old or second-hand aquarium equipment or stuff for your tank. If used, make sure to sterilize them properly before setting up the aquarium.
  3. Use high-quality food and make sure the food is not outdated. Overfeeding can also be dangerous. Thus, be careful while feeding your fish.
  4. Avoid overcrowding your tank as it gives unnecessary stress to your fish, and it is hard to clean as well.
  5. Make sure to replace the water every now and then. The use of aquarium salt has also proven beneficial as aquarium salt can kill harmful agents and protect your fish.
  6. The algae growth can also contaminate your tank and may aid in the spread of infection.
  7. Sustaining a suitable water temperature is essential to improve your fish’s immunity.


Now coming to the cure of fin rot, although the treatment might seem difficult, but, it is not impossible, and, in most cases, your fish can survive. To provide an appropriate cure, you need to know the exact cause of the infection.

  1. Clean the Aquarium

    To treat fin rot, you should clean the whole aquarium thoroughly. Use scrubbers and siphons to ensure the complete eradication of harmful substances from your aquarium.

  2. Elevate the Temperature

    Next, increase the temperature of the aquarium to a level bearable to the fish. Increased temperature is proven to kill the harmful parasite. Once your fish gets acclimatized to a high temperature, try to maintain this for a while.

  3. Specialized Chemicals

    Purchase specialized chemicals that can eliminate any growing parasite in your aquarium till the very end. Such chemicals are easily available at pet stores, and their quantity per gallon of water will be mentioned on the pack.

  4. Parasite Killers

    Such parasite killers are mostly available in powder or pellet form. Remember, these chemicals might also prove stressful for your fish; thus, avoid using them frequently.

  5. Antibacterial Medication

    Next, if bacteria cause the rot fin, then try to use antibiotics. Medication like Tetracycline, chloramphenicol, and oxytetracycline might be of great help. Mostly this medication work by cleaning the fish’s gills and improving their respiration.

  6. Anti-fungal Medication

    Sometimes, a fungal infection also leads to this deadly condition. In this case, use antifungal sprays or liquids like methylene blue, but in a small proportion.

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If the signs and symptoms don’t regress after trying all the above-mentioned solutions consult fish experts or veterinary doctors.

How to prevent fin rot from re-occurring?

The most frequently encountered problem is the re-birth of this disorder. You might think that once you have treated your fish, it might not get sick again; well, that’s not true. Actually, the reason is that despite the fish is cured but there are sometimes traces of bacteria or parasites left in the aquarium that can again lead to fin rot.

Well, to prevent fin rot from reoccurring, maintain appropriate water conditions in the aquarium. Make sure to use parasite removal chemicals 2-3 times in the following month. Clean any kind of waste as soon as possible.

When adding any new fish to the tank, make sure that it has a good immune system and is free of any disease. The poor immune condition put the fish in danger. Carefully observe the fins of the fish before buying or adding to the aquarium. Search for optimal condition according to your fish.

Before adding any decoration or plant to the tank, make sure to clean it well and make it parasite-free. Thus, your work is not finished with just curing your pet fish, but it’s important to prevent fin rot from happening again.


In order to make sure we didn’t miss any important points, we have answered few FAQs for you.

1-How long does Fin Rot take to heal?

Depending on your method of treating your fish, Fin rot can be cured in 4-5 days. With useful antibiotics, a healthy diet, clean and stable water conditions your fish will be out of danger within a short time span. Deep and severe wounds and ulcers require more time and a pristine environment to heal.

2-How do I get rid of fin rot in my fish tank?

The best-proven method to eliminating fin rot is the use of antibiotics and anti-fungal medications. Especially, Tetracycline, Erythromycin, and oxytetracycline are quite effective.
To eradicate it completely regular water changes, efficient water filtration, and aeration is necessary.

3-Will fin rot cure itself?

Fin rot can prove fatal for your fish if not treated immediately. It will not heal itself rather it will kill your fish thus immediate measures should be taken. Use broad-spectrum antibiotics, antifungals, and an effective water filtration system. It’s best to isolate the affected fish. As fish’s health should be prioritized.


Although fin rot disease is quite common and can easily kill your fish if left unattended, its elimination and cure are available. Any negligence toward the cleanliness of the tank is a major contributing factor, and a clean, healthy tank is the main precaution and treatment. We hope this article will provide you with what you seek and help you in dealing with this disease.

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