Velvet (also called Marine Oodinium or saltwater dust) is caused by the dinoflagellate parasite Amyloodinium ocellatum. The most aggressive marine fish disease - kills within 24-72 hours of visible symptoms.
Almost always from unquarantined fish. Velvet has a 12-hour to 7-day incubation; symptoms appear after the parasite has already reproduced extensively.
Multiple effective treatments exist. Pick based on your tank type, livestock sensitivity, and severity. Always treat in a separate quarantine/hospital tank - most medications are toxic to coral, invertebrates, and live rock biology.
Quarantine ALL new fish 21+ days minimum. Watch for rapid breathing within first 7 days of QT - symptoms can appear before visible spots. Velvet survives hyposalinity, so QT must use copper or TTM.
Fine gold-bronze dust appearance on body (looks like velvet). Rapid gill movement and gasping at surface. Sudden loss of appetite.
Almost always from unquarantined fish. Velvet has a 12-hour to 7-day incubation; symptoms appear after the parasite has already reproduced extensively.
Copper at therapeutic dose: Cupramine 0.35-0.5 ppm in quarantine for 21+ days. Velvet is more sensitive to copper than ich but the fish are also weaker - support with feeding-stimulant garlic or Selcon during treatment.
Quarantine ALL new fish 21+ days minimum. Watch for rapid breathing within first 7 days of QT - symptoms can appear before visible spots. Velvet survives hyposalinity, so QT must use copper or TTM.
CRITICAL - 90%+ mortality within 72 hours of symptoms if untreated
Always treat in a separate quarantine or hospital tank. Most medications are toxic to coral, invertebrates, and live rock biology.
Browse the full disease database for 45 aquarium conditions with treatment protocols, or check the care library for prevention-focused husbandry guides. Use our symptom matcher to rank likely diseases from observed signs, the water parameter checker to diagnose related water-quality issues, or the QT timeline calculator to plan a treatment schedule.