Rot is a common and serious infection in aquarium fish that can be caused by two main types of infection: bacterial and fungal. If it is not handled properly, the infection can spread to the fish’s body and cause the death of the fish. How to treat fin rot disease I will use my long experience so that the newbies can easily avoid this infection and the old ones who have been keeping fish in aquariums for a long time can also know something.
What is Fin Rot?
Fin rot is one of the most common diseases in freshwater angelfish, based on my aquarium-keeping experience. It is a bacterial disease that can be caused by Aeromonas, Pseudomonas, and Vibrio bacteria, which infect the fins, tail, and body of the fish.
Fin Rot Symptoms:
Fin rot disease usually occurs in freshwater aquariums when the water quality is poor. A common culprit is Pseudomonas or Aeromonas, as well as Flavobacterium columnare spp. Additionally, when the immune system of angelfish is weakened, fin rot occurs. Below are some symptoms based on my experience.
Fin Rot
Fin rot usually affects the tail fin of fish but can also affect other fins, such as the dorsal and pectoral fins. In the early stages of fin rot, the tip of the fin will appear ragged as the protective membrane of the fin breaks down, and there may be white dots in the affected area. As the disease progresses, the amount of fin destruction will increase, and the fin may take on a semicircular bite shape.
Note: Aquarium fish fins are delicate, and rough or sharp tank decorations or plants can easily injure them. This can cause the fins to break down and become infected with bacteria. Additionally, when the fish is bitten or attacked by other tank inhabitants, the fins of the fish may break.
Difference Between Fin Rot and Torn or Broken Fins:
- Torn or Broken: A piece of fish fin may be torn, but it will not cause discoloration and does not spread to the fish’s skin. The fish will remain active, feed, and swim normally.
- Fin Rot: The fins of the fish will turn white, brown, black, or other colors. The fish may move lazily, and the fins may appear thin, colorless, or translucent. Small holes may appear in the fins, the eyes may become cloudy, and the fish may stop feeding.
Discoloration of Fins
The fins of fish affected by fin rot become discolored. A very common symptom of fin rot is a patchy, fuzzy, white cottony coating on the tip of the rotting fin. Rotten fins may bleed and develop red streaks.
Behavioral Changes in Fish
When a fish has fin rot, its behavior changes, and it may start rubbing against the tank walls or decorations to relieve its discomfort. This actually damages its fins further, worsening the disease.
Loss of Appetite
As soon as the fish is affected by fin rot, it stops eating and becomes weak. This is evident in less movement than normal or staying closer to the bottom of the tank. The fish may swim erratically and lack agility.
Other
In the most severe stages, fin rot affects other parts of the fish’s body. For example, the belly of the fish may swell, and ulcers and sores may develop on various parts of the body. These behaviors are not only specific to fin rot, but they help confirm the diagnosis.
Reasons for Fin Rot:
Fin rot can have a number of causes, but usually, they are all environmental or bacterial infections. Once the bacteria reproduce, they invade the fin membrane. The causes of fin rot are discussed in detail below.
Bacteria: Fin rot is usually caused by opportunistic bacteria (Aeromonas, Pseudomonas, Flexibacter). These bacteria are usually harmless but can cause disease under certain conditions. They will not cause disease if the tank water quality is good.
Water Quality: The most common cause of fish fin rot is poor tank water quality. Excessive ammonia, nitrite, and phosphate can decrease the immune power of the fish, leading to health deterioration and diseases like fin rot.
Stress: Stress is another common underlying condition that weakens the fish’s immune system, reducing its ability to fight infection. Fish may become stressed due to factors like bullying by other fish or overcrowding.
Malnutrition: Fish suffer from malnutrition due to poor-quality food, which results in reduced immunity and makes them susceptible to diseases.
How to Treat Fin Rot Disease?
Fin rot treatment depends on the severity of the infection. The immune system of fish is important to keep them healthy. Once the local infection is cleared, the fish’s fins will begin to regrow, and clear or white tissue will be visible around the tail.
Cleaning and Disinfection of Tank Equipment:
- Remove the affected fish from the tank and place it in a separate tank with clean, fresh, dechlorinated water. Remove the other fish to a separate container with clean, fresh, dechlorinated water, and drain all the water from the tank.
- Remove all debris, including gravel, from the tank. Clean the tank thoroughly with hot water. Do not use soap or detergent while cleaning the tank; instead, use tank cleaning products.
- Soak the tank materials in hot water for five to ten minutes. Soak live plants in lukewarm water for 2-3 minutes, then air dry them.
pH Test of Fresh Installation and Tank Water:
- Once air-dried, put the gravel and tank accessories back into the tank. Before returning the fish to the tank, remove the damaged tissue and trim the damaged fins with a vet’s advice.
- Use a pH test kit to ensure the water quality is good. Keep the pH around 7-8, and maintain ammonia at zero and nitrate above 40 ppm. When the water is suitable for the fish, slowly add them back into the tank. Add herbal medicine first; if it doesn’t work, then use antibiotic or antifungal medicine.
Herbal Treatment Applications:
Salt and Tea Tree Oil: Keep the aquarium temperature around 75°F. Continue this treatment for 5-7 days by adding 1 teaspoon of aquarium salt per gallon of water. Long-term use of aquarium salt is unhealthy for betta fish and freshwater species, so add one to two drops of tea tree oil to keep the water clean and sterile.
Application of Antibiotic Treatment:
I have had good results using the following drugs to treat my aquarium, but a good veterinarian should be consulted for antibiotic use.
Mild Antibiotics: Fritz Mardel Maracyn, Maracyn, Waterlife- Myxazin. (Follow the dosage instructions that come with the medication for the appropriate dosage for your aquarium.)
Strong Antibiotics: BETTAFIX (follow the dosage instructions that come with the medication for the appropriate dosage for your aquarium.)
Note: Use an air pump or airstone when placing medication in the tank. When treating your sick fish with medicine, provide extra oxygen so your fish can breathe.
How to Prevent Fin Rot?
Aquarium Maintenance: Change the water once a week and clean the tank regularly to prevent future fin rot. Prune plants regularly to keep fish safe, and use specific decorations for fish with long, fine fins.
Reducing the Number of Fish in the Tank: Overcrowding your tank can cause high stress levels and increase the risk of disease.
Nutritious Food: Feed fish a diet rich in vitamins A, D, and B complex, and omega-3 fatty acids to boost their immune system. Include high-quality foods, flakes, and frozen foods. Do not overfeed the fish; only feed them as much as they can eat in about five minutes, twice a day. Overfeeding can lead to uneaten food producing ammonia and increasing the concentration of bacteria in the tank.
Water Parameters: The water temperature should be maintained according to the needs of the fish in your tank. Apart from that, other water parameters like ammonia, pH, nitrites, and others should be maintained according to the needs of the fish. If the water parameters are in accordance with the needs of the fish, their resistance to disease increases.
