Freshwater Tropical · Goldfish · Koi & Pond

Fin Rot

Progressive deterioration of fin tissue caused by opportunistic bacteria — usually a symptom of poor water quality.

Severity: Mild

Fin rot is rarely a primary disease — it is the visible end of a chain that starts with water-quality problems and ends with secondary bacterial colonisation. The fins appear ragged, the edges fray, and white-grey margins develop.

Causes

Ammonia and nitrite spikes, sustained low pH, aggressive tank-mates that nip fins (creating entry wounds), and overcrowding. The bacteria involved (Aeromonas, Pseudomonas, Vibrio) are everywhere — they just exploit damaged tissue.

Treatment

Correct water quality first — 50% water change, test ammonia/nitrite/nitrate. Treat with a broad-spectrum antibiotic like **Nitrofuracin Green** in the water for 7 days. Severe cases benefit from adding kanamycin to the food.

Recommended medications

Fin Rot

Progressive deterioration of fin tissue caused by opportunistic bacteria — usually a symptom of poor water quality.

Fin Rot

Progressive deterioration of fin tissue caused by opportunistic bacteria — usually a symptom of poor water quality.

Prevention

Weekly partial water changes, proper stocking densities, and removal of fin-nipping tank-mates.

Freshwater Tropical

Fin Rot

Progressive deterioration of fin tissue caused by opportunistic bacteria — usually a symptom of poor water quality.

Mild

Freshwater Tropical

Fin Rot

Progressive deterioration of fin tissue caused by opportunistic bacteria — usually a symptom of poor water quality.

Mild

Freshwater Tropical

Fin Rot

Progressive deterioration of fin tissue caused by opportunistic bacteria — usually a symptom of poor water quality.

Mild

Freshwater Tropical

Fin Rot

Progressive deterioration of fin tissue caused by opportunistic bacteria — usually a symptom of poor water quality.

Mild