Glossary · 🩺 Health
Fin rot
Fin rot is a bacterial condition where fins look ragged, torn or edged with white or black, almost always secondary to poor water quality or an injury — so improving the water is the first and biggest step.
It is more a symptom of a bad environment than a disease that strikes out of nowhere. Clean, stable water often lets mild cases heal on their own as the fins regrow.
Persistent or fast-spreading rot may need treatment; because it is easy to confuse with fin nipping or physical damage, observe how it progresses and get expert help if unsure.