🌿 Bryopsis Algae

Bryopsis is a particularly stubborn species of green algae that resembles tiny fern fronds or feathers. Unlike regular hair algae, Bryopsis is extremely difficult to remove manually because it regenerates from tiny fragments. The discovery that the antifungal medication Fluconazole effectively kills Bryopsis has been a game-changer for reef keepers dealing with this pest.

📋 Quick Facts

🔍 Identification

Bryopsis has distinctive features that separate it from other algae:

• Feathery appearance - Fronds with side branches like a fern
• Bright green - Vibrant green color
• Soft and delicate - Flows gracefully in current
• Grows in tufts - Clusters from a central point
• Regenerates rapidly - Grows back from smallest fragment
• Found everywhere - Rocks, coral bases, equipment

Bryopsis vs. Hair Algae

⚠️ Why It's Problematic

• Regenerates from fragments - Manual removal spreads it
• Rapid growth - Can quickly cover rocks and corals
• Difficult to eliminate - Standard algae controls don't work
• Clean-up crew won't eat it - Most herbivores avoid it
• Smothers corals - Overgrows and shades coral tissue

💊 Treatment Options

1. Fluconazole Treatment (Most Effective)

The breakthrough treatment for Bryopsis:

What is Fluconazole?

• Antifungal medication (treats yeast infections in humans)
• Sold under brand name Diflucan
• Available as generic Fluconazole
• Requires prescription in some countries (OTC in others)
• Also sold as "Flux Rx" for aquarium use

Dosing Protocol

• Dose: 20-25mg per gallon of tank water
• Calculate total system volume (tank + sump)
• Dissolve in tank water, add to high-flow area
• Single dose treatment - no repeat needed
• Leave in system for 2-3 weeks
• Run carbon after 3 weeks to remove

Example Dosing

What to Expect

• Days 1-3: No visible change
• Days 4-7: Bryopsis starts turning white/pale
• Days 7-14: Algae dies and detaches
• Days 14-21: Cleanup crew consumes dead algae
• Day 21+: Run carbon, algae should be gone

Safety Notes

• Reef-safe - Does not harm corals or fish
• Invertebrate safe - Shrimp, snails, crabs unaffected
• May affect some macroalgae - Can damage refugium chaeto
• Temporarily remove chaeto if you want to preserve it
• Well-documented success in reef keeping community

2. Manual Removal (Limited Effectiveness)

• Can reduce visible growth but won't eliminate
• Any fragments left behind will regrow
• Use only as supplement to Fluconazole
• Siphon out dead algae after treatment

3. Biological Controls (Limited)

• Sea hares - Some may eat Bryopsis
• Emerald crabs - Occasionally help
• Tangs - Most avoid Bryopsis
• Not reliable as sole treatment
• Best used to clean up after Fluconazole

4. Elevated Magnesium (Mixed Results)

• Raising magnesium to 1600-1800 ppm reported to help
• Takes weeks to months
• Results inconsistent
• May stress some corals at high levels
• Fluconazole is more reliable

⏱️ Treatment Timeline

🛡️ Prevention

• Quarantine frags - Inspect for Bryopsis before adding
• Dip corals - May dislodge small growths
• Act fast - Treat small outbreaks before spreading
• Maintain nutrients - Low nutrients slow growth

❌ Common Mistakes

• Trying to manually remove (spreads fragments)
• Underdosing Fluconazole
• Running carbon during treatment (removes medication)
• Leaving chaeto in (it may die)
• Expecting instant results (takes 1-3 weeks)
• Confusing Bryopsis with regular hair algae

📚 Summary

Bryopsis was once one of the most dreaded algae problems in reef keeping, but the discovery of Fluconazole as a treatment has made it very manageable. A single dose of 20-25mg per gallon kills Bryopsis within 2-3 weeks without harming fish, corals, or invertebrates. The key is proper identification - make sure you actually have Bryopsis (feathery, fern-like) and not regular hair algae, which requires different treatment. If you have Bryopsis, Fluconazole is the clear solution.