Causes

• According to Aquarium Life, fungal infections in betta fish often follow some other health problem like parasitic attack, injury or bacterial infection.
  
  

Dangers

• Fungal infection is contagious and can kill, so it is important that you treat and control the fungus as soon as possible.
  
  

Prevention

• Maintaining a clean tank and good filtration help to protect your betta from fungal infection. Ultraviolet sterilization also prevents fungal diseases.
  
  

Precautions

• Betta fish are more susceptible to fungus when the mucus coat on the skin is worn down because of poor water conditions or injuries.
  
  

Treatment

• After the cause of the fungus has been discovered, Aquarium Life recommends adding a solution of phenoxethol at 1 percent distilled water to your aquarium; 10 ml per liter of water is recommended. Do not repeat this process more than one time as the treatment can be dangerous to other life in your aquarium.