White Spot Disease (Ich)
Complete guide to identification, timeline, and treatment
What is Ich?
Ich (Ichthyophthirius multifiliis) is a common parasitic disease affecting both freshwater and saltwater fish. The parasite appears as small white spots on the fish's body, fins, and gills.
Symptoms
White spots on body and fins
Flashing or scratching against objects
Rapid breathing
Lethargy and loss of appetite
Clamped fins
Causes
Stress from poor water quality
Temperature fluctuations
New fish introduction
Overcrowding
Weakened immune system
Ich Life Cycle & Timeline
Day 1-3
Parasite attaches to fish. White spots become visible. Fish shows signs of irritation and flashing.
Day 4-5
Parasite matures and feeds on fish tissue. Spots increase in number. Fish becomes more lethargic.
Day 6-7
Parasite drops off fish and falls to substrate. Begins reproduction phase, creating hundreds of new parasites.
Day 8-10
New parasites (tomites) swim freely seeking hosts. This is when treatment is most effective. Cycle repeats if untreated.
Treatment Protocol
- Raise temperature to 28-30°C (82-86°F) to speed up parasite life cycle
- Add aquarium salt (1 tablespoon per 5 gallons) for freshwater fish
- Use copper-based medication or formalin/malachite green treatment
- Perform daily 25% water changes to remove free-swimming parasites
- Continue treatment for 10-14 days to break the complete life cycle
- Quarantine new fish for 2-4 weeks before adding to main tank
Important
Treatment differs between freshwater and saltwater fish. Always remove activated carbon from filters during treatment. Some fish species (like scaleless fish) are sensitive to certain medications - consult species-specific guidelines.