đĻ Marine Ich & Velvet Disease
Marine Ich (Cryptocaryon irritans) and Marine Velvet (Amyloodinium ocellatum) are two of the most deadly parasitic diseases in saltwater aquariums. Both can wipe out entire fish populations within days if not treated promptly. Understanding the differences between them and knowing proper treatment protocols is essential for every reef keeper.
đ Quick Facts
| Disease | Marine Ich | Marine Velvet |
|---|---|---|
| Pathogen | Cryptocaryon irritans | Amyloodinium ocellatum |
| Appearance | White salt-grain spots | Gold/rust dust coating |
| Severity | High - Fatal if untreated | Critical - Rapidly fatal |
| Progression | Days to weeks | Hours to days |
| Treatment | Copper, tank transfer | Copper, chloroquine |
đ Identification
Marine Ich (Cryptocaryon)
- White spots - Distinct salt-grain sized white dots
- Spots vary - Number changes day to day
- Flashing - Fish scratching against rocks
- Rapid breathing - As gills become affected
- Lethargy - Reduced activity
- Loss of appetite - May stop eating
- Progression - Develops over days to weeks
Marine Velvet (Amyloodinium)
- Dusty coating - Fine gold/rust powder appearance
- Affects gills first - Rapid breathing before visible spots
- Film on body - Appears like velvet fabric sheen
- Extreme lethargy - Fish may lie on bottom
- Rapid progression - Can kill within 12-24 hours
- Clamped fins - Fins held close to body
- Much more deadly - Higher mortality than ich
Key Differences
| Feature | Ich | Velvet |
|---|---|---|
| Spot size | Larger, distinct | Fine, dust-like |
| Color | White | Gold/rust |
| Pattern | Scattered spots | Uniform coating |
| Speed | Days to weeks | Hours to days |
| Mortality | High if untreated | Very high, rapid |
đ Treatment Options
CRITICAL: Cannot Treat in Display Tank
Effective treatments are NOT reef-safe. You must either:
- Remove fish to hospital/quarantine tank for treatment
- Leave display tank fallow (fishless) for 76+ days
- There is NO effective reef-safe treatment
1. Copper Treatment
Gold standard for both diseases:
- Copper Power or Cupramine (chelated copper)
- Maintain therapeutic level: 2.0-2.5 ppm (Copper Power) or 0.5 ppm (Cupramine)
- Test copper levels twice daily
- Treat for minimum 30 days at therapeutic level
- Use separate hospital tank (copper kills invertebrates)
- Never use copper in display tank with corals/inverts
2. Tank Transfer Method (TTM)
Copper-free option for sensitive fish:
- Move fish to new clean container every 72 hours
- Parasites fall off fish but can't reattach in new water
- Requires minimum 4 transfers (12 days)
- Best combined with fallow period for display
- Labor intensive but effective
3. Chloroquine Phosphate
Alternative treatment, especially for velvet:
- Dose: 40mg per gallon
- Effective against both ich and velvet
- Easier to maintain than copper
- Can be combined with copper for severe cases
- Still not reef-safe
4. Fallow Period (Display Tank)
While treating fish separately:
- Leave display tank without fish for 76 days minimum
- Parasites die without fish hosts
- Corals and invertebrates are fine
- Temperature of 80-82°F speeds parasite lifecycle
- Essential for preventing reinfection
â ī¸ Emergency Response (Velvet)
If you suspect velvet, act immediately:
- Move fish to hospital tank NOW
- Begin copper treatment immediately
- Freshwater dip can provide temporary relief
- Velvet kills in hours - don't wait to observe
- Better to treat unnecessarily than lose all fish
đĄī¸ Prevention
- Quarantine ALL new fish - 30 days minimum
- Prophylactic treatment - Consider treating in QT before display
- UV sterilizer - Kills free-swimming parasites (reduces, doesn't eliminate)
- Reduce stress - Stressed fish more susceptible
- Proper acclimation - Minimize stress during introduction
- Don't share equipment - Nets, containers can transfer parasites
- Healthy diet - Well-fed fish have stronger immune response
â Common Questions
Can ich/velvet go away on its own?
No. Healthy fish may survive an initial outbreak, but parasites remain in the tank and will eventually kill fish during stress or weaken them over time. The only way to eliminate these parasites is proper treatment and fallow periods.
Will "reef-safe" treatments work?
No. Products marketed as reef-safe ich treatments (garlic, herbal remedies, etc.) do not kill these parasites. They may boost fish immune response slightly but will not cure an infection. Only copper, chloroquine, or tank transfer are effective.
How did my fish get infected?
Almost always from new fish additions that weren't properly quarantined. Ich and velvet parasites can survive on fish that appear healthy, only to multiply when conditions favor them.
â Common Mistakes
- Using "reef-safe" ich treatments (they don't work)
- Treating in display tank (kills corals/inverts)
- Not maintaining therapeutic copper levels
- Ending treatment too early
- Not doing fallow period (reinfection guaranteed)
- Returning fish before 76-day fallow complete
- Skipping quarantine for new fish
đ Summary
Marine ich and velvet are serious diseases that require aggressive, proven treatment methods. There are no shortcuts or reef-safe alternatives that actually work. The protocol is: remove fish to hospital tank, treat with copper or chloroquine for 30+ days, and leave display fallow for 76+ days. Prevention through proper quarantine is far easier than dealing with an outbreak. If you suspect velvet, act within hours - it's far more deadly than ich and progresses extremely rapidly.