My fish has fin rot

Fin rot: diagnosis, causes & treatment

The fin rot is one through bacterial pathogens triggered disease that leaves unsightly damage to the fins. The disease can affect almost all species of ornamental fish.

On this page you can find out how to recognize the disease and which one causes are responsible for how to use them be trades and whether the fins grow back.

Symptoms of fin rot

The symptoms are clear. The fins show more and more damage as the disease progresses. you fading, become milky, to get Holes and fray. Most often the disease spreads from the edge of the fin towards the base of the fin out. The damaged fins change that too Swimming behavior. Diseased fish also separate themselves from the group and rub against objects. Summary of all symptoms:


  • frayed fins
  • white spots on fins
  • Holes in the fins
  • Fin base inflamed red
  • The edges of the fin can become inflamed red


  • social isolation
  • apathetic behavior
  • Fin clamps
  • Unwillingness to eat
  • unusual movements
  • Fish rub against objects


Fin rot is one bacterial disease. The responsible bacterial pathogens of the genera Aeromonas andPseudomonas are found in many aquariums without fish getting sick with fin rot. Only when the immune system is through stress or Other diseases is weakened, the disease breaks out. The most common reasons for stress are too high a stocking density, incorrect socialization, incorrect nutrition or poor water hygiene.

Often the fin rot occurs as Secondary illness bacterial infectious diseases such as fish tuberculosis. In addition, there is often additional fungal infection of damaged fins, which makes treatment more difficult.


The chances of treatment for fin rot are very good in the early stages. Since the disease can be recognized by its appearance and behavior, one succeeds early diagnosis in many cases. Since fin rot spreads very quickly, depending on the case, immediate action is required. If the fin rot is not treated in time, the entire fin disappears, the body is damaged and the fish dies.

Eliminate stressors

Stress weakens the immune system of the fish and is often to blame for the outbreak of fin rot. Possible stress factors are ...

Bad water quality

When the water quality is poor, the bacteria responsible for fin rot multiply faster. Regular Water change and Cleaning work are necessary for the well-being of the fish. In addition, the regular controll the most important water values ​​(ammonium, ammonia, nitrite, nitrate etc.) are necessary to avoid stress caused by poor water quality and the multiplication of pathogens.

Too high stocking density

Too high a stocking density creates social stress. In addition, the water is more heavily polluted by excretions.

Unsuitable food

The wrong food can Deficiency symptoms and cause stress. In the case of fin rot, fish should especially rich in vitamins and every now and then with Live food to be fed. It is important to know which food your fish prefer. In order for the fish to stay healthy in the long term, you should continue these good feeding habits after the treatment.


With the medication JBL Ektol or that Sera Bactopur fin rot can be successfully treated. Treatment with medication fights the responsible bacteria. Drug treatment should be started quickly to increase the chances of success. But don't think that drug treatment alone will get you far. Your fish are doing better in the short term, but in the long term you also have to improve the keeping conditions and water quality, as well as avoid stress.

JBL Ektol fluid Plus

€ (May 16, 2021 11:00 pm)

Quarantine tank

To get additional Avoid stress, it is worthwhile to put the sick fish in a quarantine tank. In this one can Use medicationwithout harming the other fish & invertebrates. In addition, the sick fish in quarantine is not exposed to any stress from healthy fish and that The risk of infection and spread is reduced.

Vitamin preparations

Vitamin supplements like that VitaMixvon Dennerle can support healing. Even after the pathogens have been fought, vitamin preparations accelerate them Healing of the fins.

JBL Atvitol multivitamin

6.19 € (May 16, 2021 11:00 pm)

Do the fins grow back?

Fins usually grow back, similar to fingernails in humans. In exceptional cases the disease has progressed so far that the Fin base is damaged. In these cases, the fins no longer grow or only partially grow back. Prerequisites for the healing of the fins are one Species-appropriate and vitamin-rich feeding and the Avoiding stress.

Prevent fin rot

The fin rot is one Factor disease. This means that the pathogens can normally be found in the aquarium without the disease breaking out. However, factors such as previous illnesses or stress weaken the immune system and the disease can break out. Through the following activities stress can be avoided and the immune system strengthened:

  • Feed live feed
  • Preventive vitamin enrichment of the water
  • Regular maintenance and cleaning
  • Control of all important water values
  • Pay attention to socialization and stocking density