Fin Rot Treatment

fin rot treatment

Fin rot is a common disease among fishes. This disease is also called tall decay and is a bacterial disease. Fin rot generally starts around the edges of the fish’s fin. It then spreads over a larger area destroying other tissues of the fish. The primary bacterial infection responsible for this fin rot disease is Pseudomonas fluorescens. This disease can also be caused due to some fungal infection termed as fungal fin rot. This disease can even cause serious illness to the fish and thus, shrink its capacity to make any movement. Now, to gain a better understanding of the best fin rot treatment, it is crucial to learn the primary symptoms of the fin rot.

To know more about different Saltwater and Freshwater Aquarium Fish Diseases, click this article “Aquarium Fish Diseases: Causes, Symptoms, and Treatments“.


Now, as we know that if left unchecked, fin rot can be very dangerous as it can even paralyze the fish’s free movement in the water and cause lifetime damage to its fins.

Thus, it is crucial to know the primary symptoms of fin rot.

  • The fins of the fish get deformed due to fin rot. The three fins that are the dorsal, pectoral and the tail fin get equally affected by this disease. Initially, the fins get destroyed at a smaller scale and then spreads to a larger area of the fin shedding it away.
  • This fin rot disease also develops a hole in the fungal infected fin.
  • Now the fin can also become colorless or develop white dots. The fins edges at times turn black or brown, and a red streak extends on it due to bleeding.
  • In case of severe infection, the fin even swells up, generating ulcers on the fish’s body.
  • Now, the bacteria may also get inside the fish’s blood, mixing up with the blood.
  • Lastly, the fish becomes listless due to the advance of the fin rot disease.

Thus, these symptoms go a long way into identifying the disease at an early stage and make one aware of the development of severe bacterial and fungal infection.

Causes of fin rot

Fin rot or tall rot is caused by bacteria, such as Aeromonas, Pseudomonas, and Flexibacter which, if left unchecked, can be very dangerous. A significant cause for this disease-causing bacteria in contaminated water. When the fish tank is overcrowded, it makes the fish tank dirty and contaminates the water in the fish tank. Also, overfeeding causes the fish to sweat more, thus, giving way to the development of ammonia and nitrite, which are the base for the fin rot disease. This overcrowding stress up the fish and at times due to fighting with other fishes or nipping of the fins, the fin rot disease may occur.

By understanding these fin rot causes, one can now get a better idea of how to treat the disease in the fish.


Fin rot disease is a prevalent disease among the fishes and is also an easily curable disease.

We can now get a better understanding of the treatment of fin rot.

  • The very primary step for the treatment of fin rot is to clean the tank properly. Now, for cleaning the tank, move the affected fish in a different tank. However, place the infected fish in isolation and the other fish in some separate tank.
  • Fill the fish tank with unchlorinated water. Use hot water and avoid any chemicals or soap and shampoos for the cleaning of the fish tank. The gravel of the fish tank should also be cleaned.
  • Now, it is also very essential to clean the tank properly. After the tank is thoroughly cleaned and the bacteria have completely been established in the fish tank, one can change the water of the fish tank partially. The water in the fish tank should be changed somewhat so that the beneficial bacteria are not washed away.
  • Also, clean the tank’s water filter to get rid of the minutest of infection prevailing in the fish tank. Try to remove all the dirt stuck in the inside and outside of the filter.
  • Furthermore, the pH level of the tank water, it is now essential to take out the pH reading of the tank water. One can always use a pH test kit for the required testing process. The water should be completely free from ammonia, nitrite, and nitrate. The pH reading is required to be not more than 7 or 8.

Further, as one has thoroughly cleaned up the fish tank, the fish can be properly put back in the tank and then several antibiotics and antifungal medicines can be used to ensure complete clearance of fin rot disease.

Medicines for Fin Rot

Several antibiotics and antifungals can be used to get rid of the fin rot disease. It is advisable to do the medicinal treatment only in case the steps as mentioned above, don’t work in fixing the fin rot.

Several fin rot antibacterial medicines are available at However, while purchasing these medicines, one needs to have proper knowledge of their fish’s kind. There are different kinds of fishes: goldfish, Betta fish and tropical fish. Various medicines are available of different types such as for tropical fish fin rot one can not use the same medication used for goldfish fin rot or Betta fish fin rot.

Since these medicines comprise of the antibiotics responsible for killing the fungal infections, it is recommended to give the proper dosage of the drug to the fish. These fin rot medicines contain erythromycin, minocycline, trimethoprim, and sulfadimidine.

Now, the best medicine for fin rot treatment can be Tetracycline. Also, other medications such as Jungle Fungal Eliminator, Maracyn, Maracyn 2 WaterlifeMyxazin, and Melafix are used for the fish fin rot treatment.

One can also use a tea tree oil for the treatment of fin rot in fish. However, it is advisable to use this tea tree oil in the initial stages of the disease and as a preventive method. Tea tree oil should be used along with the antibacterial medicines for a better outcome.

While using tea tree oil, first start by pouring one or two drops of the oil and observe the reaction of the oil on the fish. Proceed with this treatment only in case the fish reacts to the tea tree oil positively.

Also, there are recommendations for treating fin rot with salt. One can either use tonic salt or sodium chloride salt for this purpose. One tablespoon of the marine salt should be added in one gallon of fish tank water. However, restrain from using iodized table salt.

While medicating the fish, it is required to fill the fish tank with a higher oxygen level so that the fish doesn’t suffocate in the fish tank since the medicine pulls away from the oxygen.

For supplying extra oxygen, one can always use an air pump or an airstone.

How to prevent fin rot

Now, to avoid rot fin disease, one needs to follow these necessary steps:

  • Firstly, clean the tank properly every week so that it doesn’t develop any unwanted substance inside the water.
  • Also, change the water in the fish tank, partially, twice a week since contaminated water generally gives rise to some bacterial or fungal fin rots.
  • One can add some marine salt in the water tank to ensure a disease-free environment for the fish. Furthermore, the pH of the fish tank should be monitored regularly.
  • Overcrowding the fish tank can also result in fin rot disease as due to irritation and stress, the fish might end up biting each other.
  • Now the fish should be given a proper diet. Inadequate and low-quality food can result in the occurrence of fin rot disease. One must also try to avoid overfeeding the fish as the fish then starts excreting more. This increases the decomposed matter which is responsible for producing ammonia and nitrite.
  • Remove any leftover from the fish tank to maintain hygiene.


Through this article, we also have the basic idea of how to treat the fin rot disease and the various basic methods of treating the same. For a better understanding of the disease, we have discussed reasons responsible for the occurrence of the disease. Furthermore, the essential medicines mentioned above also go a long way in curing the disease which had already affected the fish in the tank. On can even follow the treating of the disease with salt.

Since the answer to the question, Is fin rot contagious? it is possible, so avoid mixing up the fish with the other fishes in the tank and take immediate steps to get rid of the disease so that, it doesn’t paralyze the fish’s movement or permanently damage its tissues.

To know more about different Saltwater and Freshwater Aquarium Fish Diseases, click this article “Aquarium Fish Diseases: Causes, Symptoms, and Treatments“.