Marine Ich (Cryptocaryon)
Complete guide to identification, timeline, and treatment
What is Marine Ich (Cryptocaryon)?
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
Marine Ich (Cryptocaryon) 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 82-86°F (28-30°C) to speed up parasite life cycle
- Use copper-based medication — most effective for Marine Ich
- Try hyposalinity: lower salinity to 1.009 specific gravity for 3-4 weeks
- Perform daily 25% water changes to remove free-swimming parasites
- Continue treatment for 10-14 days to break the complete life cycle
- Quarantine all new fish for 30-45 days before adding to display tank
Important
Always treat fish in a quarantine tank. Copper and hyposalinity treatments will harm invertebrates and live rock. Never treat your display reef tank directly.