How Do I Get Rid of Hair Algae in My Reef Tank?

Hair algae is one of the most common and frustrating problems reef keepers face. The good news? It's almost always fixable with the right approach.

What Causes Hair Algae?

Hair algae thrives when your tank has an imbalance of:

• Excess nutrients - High nitrates (>20 ppm) or phosphates (>0.1 ppm)
• Too much light - Long photoperiods or intense lighting
• Insufficient competition - Not enough corals or macroalgae to compete for nutrients

Step-by-Step Removal Plan

1. Manual removal - Use a toothbrush to scrub rocks (outside the tank) or twist algae around a skewer to pull it out
2. Reduce feeding - Cut back to every other day and only feed what fish consume in 2 minutes
3. Increase water changes - 10-20% weekly using RO/DI water
4. Add phosphate removal - GFO (granular ferric oxide) or a phosphate reactor works wonders
5. Shorten photoperiod - Reduce lights to 6-8 hours during the battle

Best Cleanup Crew for Hair Algae

A strong cleanup crew can make a huge difference. The best hair algae eaters include:

• Sea urchins - Tuxedo and pincushion urchins are hair algae machines
• Turbo snails - Mexican turbos are voracious algae eaters
• Emerald crabs - One of the few crabs that actively eat hair algae
• Tangs - Kole, yellow, and bristletooth tangs love to graze

Prevention Tips

Once you've won the battle, keep hair algae from returning:

• Test phosphate weekly - use the ReefBay app to track trends
• Run GFO or Phosban continuously
• Don't overfeed
• Use RO/DI water for top-offs and water changes
• Keep a healthy cleanup crew at all times

Most reefers beat hair algae within 4-8 weeks of consistent effort. Stay patient and track your parameters!