Fin rot causes

Fin rot causes

The causative agent of fin rot is the bacterium Pseudomonas fluorescens. It lives in natural reservoirs and enters the home tank through food, soil, decor, or from new fish from the store that has not passed quarantine.

The infection destroys the fins of the fish, they become torn, worn out, injured. Inexperienced aquarists think that this is mechanical damage, so they do nothing, pets die. The danger is that there is little time for treatment, the disease develops rapidly.

The main causes of infection are:

  • dirty water, lack of filter;
  • untimely or poor cleaning of the aquarium;
  • non-compliance with the desired temperature regime;
  • increased acidity;
  • stress factors (so you need to take care of the comfortable existence of fish, choose the right decor, additional equipment).

Symptoms of the disease:

If you notice the following condition even in one fish, immediately proceed to treatment:

  • The color change of fins. They turn light blue. Cloudiness begins from the edges, spreads to the entire organ. This symptom is clearly visible in fry with transparent feathers;
  • Clogging of blood vessels, which manifests itself in the form of red stripes, spots;
  • Rot starting at the edges;
  • Blurred eyes;
  • Breaking off fins;
  • Ulcers throughout the body (manifest in the last stage of the disease)

Fin rot can be seen in the pictures, inexperienced owners of aquariums often do not notice it.

Which fish are susceptible to disease?

All species of fish can become infected, especially if the immune system is weakened, but more often fin rot occurs in inhabitants with large, long, folded fins:

  • in Xiphophorus  (fins slowly decrease, tail erosion begins, white plaque appears);
  • in goldfish (the edges of the fins become cloudy, split, become short);
  • in guppies (at first, the fins fade, become thin, disappear);
  • in angelfish (red stripes appear, then ulcers);
  • in betta fish(in these species, rot can be seen immediately, since they have a red color, which changes to white-blue);
  • in cichlids (white plaque, destruction of the fin rays and the entire tail).

Similar symptoms are observed in barbs, catfish, oscars , zebrafish. If the fish are very young – the disease is more complicated, often fatal. An individual approach is needed in the treatment of fish, angelfish, for example, should not be kept in a separate tank, they do not tolerate movement from aquariums well, and bettafish recover only in quarantine.

The initial stage of the disease

Treatment of fin rot in a common aquarium should be started immediately; it is easy to neutralize the infection at an early stage. Carefully move the infected fish to a separate tank with purified water. Do the same with the other inhabitants. The aquarium is freed because it needs to be thoroughly cleaned. At the initial stage, an elementary change in the living conditions of the fish and the destruction of the infection with drugs help. The water is heated to the maximum possible temperature, salt is added, if this is acceptable for this type. In 90% of cases, these actions help.

fin rot

Transition to Intensive Care

How to treat fin rot in a common aquarium if improving conditions do not help? There are many options. These are folk methods, popular antibiotics, antibacterial agents. Tetra General Tonic, Tetra Goldfish GoldMed, Sera Bactopur and Omnipur, tripaflavin, have proven themselves well. They contain an antibiotic, so bacteria are easily killed. But make sure that the preparations do not contain dyes, they will kill pets. Of the more affordable treatment options for fin rot, the following should be noted:

  • Chloramphenicol. One tablet is diluted in a small amount of water, the solution is poured into a common tank in a ratio of 1:20. Treatment with chloramphenicol is repeated every 3 days;
  • Sulfanilamide. It is bred in warm water (27 degrees), poured into a vessel, or separate baths are made for infected fish.
  • Bicillin 5. Treatment with bicillin-5 lasts 6 days, each time one part of the bottle is consumed. During the application, it is recommended to darken the aquarium; in light, the antibiotic decomposes. Drawback – kills living ornamental plants;
  • Biseptol-480. For 5 liters, 1/8 of the tablet is enough. Fish should be constantly in this solution, it is important to provide aeration.
  • The salt. The standard dosage is 1 tbsp. spoon per 10 liters of water. The fish is placed in such a bath for half an hour twice a day. To cure Megalechis thoracataand or Cory catfish, concentration should be reduced;
  • Furatsilin. Treatment in a general aquarium with furacilin lasts up to 2 weeks, sometimes twice a day is enough. The required amount per 30 liters is 1 tablet of 0.02 grams. The drug does not have a negative effect on the health of fish and the bio-balance of water. It is not necessary to remove filters during application;
  • Antipar Treatment. This is a special solution for the treatment of ornamental fish based on malachite blue, malachite green, formalin. It’s better to use it in the evening before bedtime,
  • Hydrogen peroxide. Need a 3 percent solution. It is dissolved in a separate container, then added to the aquarium. If you pour it directly into the tank – you can easily burn the fish. The treatment will take from 1 to 2 weeks. Peroxide oxidizes and destroys the organics of bacteria, so do not forget to constantly change part of the water.
  • Malachite green. It is needed in the form of oxalate, other types are toxic. It can stain objects and harm the bio-balance of the underwater microcosm. Not effective in an alkaline environment. Used to process fish in the bath.

Give antibiotics according to the instructions no longer than the prescribed time. Any medicine for fin rot absorbs oxygen, so you need to enrich them with aquarium water by installing a compressor or air spray.


To minimize the likelihood of fish becoming infected with the disease, regularly change the water in the aquarium, for small tanks – once every 3 days, for large ones – once a month. Do not forget to wash decorative items, gravel. It is advisable to add special salt to the water. Choose the fish, taking into account not only your own tastes, but also the advice of specialists. For example, angelfish, pufferfish, and catfish bite the tails of friendlier fish. Do not overpopulate the tank, pets don’t need stress, and underwater inhabitants become aggressive in such cramped conditions. Make sure that the decorative accessories resemble the fish’s native habitat and they can hide. A good option – grottoes, driftwood, shells. But make sure that all the decor is safe, mechanical damage in dirty water is a direct path to infection.

Do not save on feed, choose products from trusted manufacturers that monitor the quality of the product. Follow the regime, give it at one time. Vitamins for enhancing immunity will be good too. Overfeeding fish is not worth it. Leftovers are additional bacteria.