[header] How to treat fungal infections in fish [title] Identify your fish's disease. [step] Fungal infections show up in a variety of different ways. [substeps] Sometimes, and most commonly, your fish will develop a white film or white patches over parts of its body. 
This may seem like discoloration, but a closer look often reveals a white, fungus-like growth. Another sign of a fungal infection is pop-eye.