Fin rot is a common disease that describes the rotting or fraying of a fish’s fins or tail. If you suspect that your fish may be suffering from fin rot, take a close look at their fins and tail for the following symptoms:

  • Fins or tail appear to have frayed edges
  • The fin or tail edges have turned white, or even black and brown in some cases
  • Inflammation at the base of the fin
  • A part of the fin or tail may have rotted away or fallen off

These symptoms are often accompanied by a loss of appetite, less activity, and your fish sitting at the bottom of the tank.

Fin rot is most often caused by a dirty tank and poor water quality, poor care, or exposure to other fish who may have contagious diseases. Fin rot can also be caused by injuries such as mishandling of fish or nipping and bullying behaviours from other tank mates.

How to treat your fish for fin rot:

  1. Syphon the gravel at the bottom of the aquarium to remove any waste and debris.
  2. Do a 25% water change of your fish tank
  3. Check and monitor your water conditions. Test for factors like pH, temperature, chlorine, ammonia, nitrite and nitrate levels. You can test for these with a home water testing kit or head into your nearest Petbarn with a 100ml sample of your tank water for a free water test.
  4. Move the affected fish to a quarantine tank if not all fish show signs of fin rot with a separate net. This is important to prevent the fin rot from spreading to other fish. It is also a good idea to move the fish if it is being bullied by tank mates to prevent further nipping.
  5. Treat the affected fish tank with Blue Planet’s Tri-Sulfa Tablets, API Stress Coat, Melafix or a vet prescribed antibiotic following the product label’s instructions.
  6. Remove the active carbon from the filter during treatment.
  7. Monitor your fish every day to check if the fin rot has stopped. If treatment is successful, you may notice that the damaged fins and tail will slowly grow back after a few weeks.

It is important to treat your fish for fin rot as soon as you possible to prevent further rotting and harm to your fish. If caught early, fin rot can be treated, and your fish’s fins will slowly grow back with care and time. In more serious cases where the fin rot has reached the body of the fish, the tissue will not regenerate.

How to Prevent Fin Rot

The best way to prevent fin rot, as well as many other fish diseases, is to keep your water clean and aquarium in tip-top shape.

Regular water changes keep your tank clean and regular water testing can help you pick up any problems with water quality before bacteria can build up and lead to fin rot.

Try to not overcrowd your tank as waste can build up quickly, and fish may nip at one another. Even though fish are calming and peaceful to watch, not all types of fish get along. Always check for the compatibility of your fish before adding new tank mates to prevent any fin nipping or fighting between your fish friends.

When feeding your fish, feed small quantities of fresh, high-quality food. As a rule of thumb, your fish should consume the food that you feed them within a few minutes. Any food that they do not finish can contribute to bacteria and waste build up in your tank and cause fin rot. Feeding time is also a good time to carefully observe your fish’s behaviour. Keep a daily eye out for any changes to their fins, tail, body, appetite and behaviour.