parasite · both

Gold Dust Disease (Velvet variant)

Gold dust disease (Piscinoodinium) is the freshwater version of velvet. Fine gold/yellow dust appearance on fish body. Very fast-spreading - kills entire tanks if untreated.

Severity: CRITICAL - 90%+ mortality if untreated

Symptoms

Cause

Piscinoodinium parasite. Spreads via free-swimming dinospores. Stress + low immunity = outbreak.

Treatment

Always treat in a separate quarantine tank. Most medications are toxic to coral, invertebrates, and live rock biology.

Copper sulfate (freshwater). For QT only - kills inverts + plants. 7-10 day treatment.
Ich-X + heat. Raise tank to 86°F + dose Ich-X for 7 days. Less aggressive than copper.
Salt + heat. 1 tablespoon salt per 5 gallons + 86°F for 14 days. Effective + safe for most species.

Prevention

Quarantine new fish 14-21 days. Maintain stable parameters.

Related

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.