Zoanthids (often called "zoas") are the gateway drug of coral keeping. They're colorful, hardy, affordable, and come in hundreds of named varieties. More importantly, they're one of the few corals that genuinely thrive in nano reef conditions.
Why Zoas Are Perfect for Nano Tanks
Zoanthids tolerate a wider range of parameters than almost any other coral. They'll grow in low to moderate light, don't need perfect water chemistry, and propagate readily.
Water Parameters for Zoanthids
Temperature: 76-80°F (aim for 78°F and keep it stable) Salinity: 1.024-1.026 specific gravity Alkalinity: 7-11 dKH Nitrate: 2-20 ppm (zoas actually like slightly "dirty" water)
Lighting Requirements
PAR range: 80-200 PAR is the sweet spot. In a nano tank with an AI Prime 16HD, this means placing zoas in the middle to lower third of the tank.
Color and light intensity: Many zoa varieties show their best colors under moderate, not high, light.
Common Zoanthid Problems
Zoa Pox
Small white bumps on the polyp mat. Treatment: freshwater dip for 5-7 minutes, then improve water quality.
Zoa-Eating Nudibranchs
Nearly invisible — small, translucent slugs. Always dip new frags in CoralRx before adding them to your tank.
Recommended Beginner Varieties
Eagle Eyes: Classic green with orange center. Bulletproof. Bam Bams: Bright orange. Fast growers. Purple Death: Deep purple. Dramatic under blue lighting.
The Zoa Garden Approach
Many nano reef keepers build entire tanks around zoanthids. Fill your rockwork with diverse varieties, creating a patchwork of color. Pair with clownfish and a cleanup crew for a stunning, maintainable nano reef.