28/09/2026
🐟⚠️ FUNGAL DISEASE vs BACTERIAL INFECTION: CAN YOU TELL THE DIFFERENCE?
Not every sick fish has the same problem. A fish with a wound, skin damage, or unusual growth may be dealing with bacteria, fungi, or even more than one problem at the same time.
Knowing the difference can help you avoid treating blindly. 👇
🍄 FUNGAL PROBLEMS
Fungal growth often appears as white, grey, or cotton-like material on the skin, fins, eggs, or an existing wound.
It commonly takes advantage of fish that are already:
• Injured 🩹
• Stressed
• Weak or sick
• Exposed to poor water conditions
• In contact with dead organic matter
🦠 BACTERIAL INFECTIONS
Bacterial infections can cause different signs, including:
• Open or worsening wounds
• Redness or bleeding
• Skin ulcers
• Fin damage or fin rot
• Swollen areas
• Loss of appetite
• Abnormal swimming
⚠️ HERE IS THE IMPORTANT PART:
A cotton-like growth does not automatically mean the original problem was fungal.
For example, a fish may first suffer a bacterial infection or physical injury, and the damaged area can later become colonised by water mould.
💧 DON’T FORGET THE WATER
Poor water quality, overcrowding, injuries, stress, and accumulated waste can make fish more vulnerable to disease.
Before reaching for medication, check:
✅ Dissolved oxygen
✅ Ammonia
✅ Nitrite
✅ pH
✅ Temperature
✅ Stocking density
✅ Feeding and waste management
🐟 The goal is not just to treat what you can see. Find out what started the problem.
Observe → Investigate → Identify the likely cause → Then take appropriate action.
