🟡 Freshwater Velvet (Oodinium)

Freshwater velvet, caused by the parasite Piscinoodinium pillulare (also called Oodinium), is one of the deadliest diseases in freshwater aquariums. It progresses faster than ich and has a higher mortality rate. The telltale gold or rust-colored "dust" on fish requires immediate aggressive treatment.

📋 Quick Facts

Pathogen	Piscinoodinium pillulare (dinoflagellate parasite)
Appearance	Gold/rust dust coating, velvet sheen
Severity	Critical - Rapidly fatal without treatment
Speed	Can kill within 24-48 hours
Treatment	Copper, darkness, heat

🔍 Identification

Velvet can be difficult to spot early:

Fine gold/rust dust - Much finer than ich spots
Velvet sheen - Shimmer when light hits fish
Rapid breathing - Often first symptom (attacks gills)
Flashing/scratching - Fish rub against objects
Clamped fins - Held tight against body
Lethargy - May lie on bottom
Loss of appetite - Stops eating
Rapid decline - Gets worse very quickly

Velvet vs. Ich

Feature	Velvet	Ich
Appearance	Fine gold dust	White salt grains
Color	Gold/rust/yellow	White
Size of spots	Very fine	Larger, distinct
Speed	Very fast (hours)	Slower (days)
First symptom	Rapid breathing	Visible spots
Mortality	Very high	High

⚠️ Why It's So Dangerous

Attacks gills first - Fish suffocate before you see spots
Extremely contagious - Spreads rapidly through tank
Hard to detect early - Fine dust easy to miss
Fast progression - Can kill in 12-24 hours
Photosynthetic - Parasite uses light for energy

💊 Emergency Treatment

Act IMMEDIATELY

If you suspect velvet, begin treatment NOW. Don't wait to confirm.

1. Dim/Eliminate Lights

Turn off tank lights immediately
Cover tank to block ambient light
Darkness weakens the parasite
Maintain throughout treatment

2. Raise Temperature

Increase to 82-86°F (28-30°C)
Speeds parasite life cycle
Makes treatment more effective
Increase aeration (warm water holds less oxygen)

3. Copper Medication

Copper is the most effective treatment
Cupramine or Copper Power recommended
Follow dosing instructions exactly
Test copper levels with kit
Maintain therapeutic level for 14+ days
Warning: Copper kills invertebrates

4. Salt (Supplemental)

Add 1-3 tsp per gallon
Helps with osmoregulation
Some antiparasitic effect
Not sufficient alone for velvet

Alternative: Malachite Green + Formalin

If copper not available
Products like Ich-X contain these
Less effective than copper for velvet
Follow package directions

⏱️ Treatment Timeline

Time	Action
Hour 0	Lights off, cover tank, begin raising temp
Hours 1-2	Add copper medication, increase aeration
Days 1-3	Maintain darkness, temp, copper level
Days 3-7	Should see improvement, continue treatment
Days 7-14	Continue full treatment, don't stop early
Days 14+	Gradually return to normal, monitor closely

🛡️ Prevention

Quarantine all new fish - 2-4 weeks minimum
Reduce stress - Stressed fish more susceptible
Maintain water quality - Regular testing and changes
Avoid temperature swings - Keep stable
Don't overcrowd - Stress and disease spread
Prophylactic treatment - Consider copper QT

❌ Common Mistakes

Waiting to see if it's "really" velvet (fish die)
Using ich treatment only (not strong enough)
Not maintaining darkness throughout treatment
Stopping treatment when fish look better
Not quarantining new fish
Using copper in shrimp/snail tanks

📚 Summary

Freshwater velvet is a medical emergency. The combination of darkness + heat + copper medication gives the best chance of survival. Time is critical - if you even suspect velvet, begin treatment immediately. The parasite's use of photosynthesis makes darkness an essential part of treatment, not just medication. Complete the full 14-day treatment even if fish appear recovered. Prevention through quarantine is far easier than treating an outbreak. If you lose fish despite treatment, thoroughly clean and sterilize equipment before adding new fish.

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