Pachyclavularia violacea
| Care Level | Easy — great beginner coral |
| Lighting | Low to moderate |
| Water Flow | Moderate |
| Placement | Anywhere — rock or a dedicated island |
| Aggression | Peaceful, but spreads aggressively |
| Coloration | Bright green polyps on a purple mat |
Overview
Green Star Polyps (GSP) are one of the hardiest and most popular beginner corals, forming a spreading purple encrusting mat covered in shimmering green polyps that sway beautifully in the current. They are extremely forgiving of imperfect water and lighting, making them a favorite first coral.
Care & Placement
GSP will grow on almost any surface under low-to-moderate light and flow. Because it encrusts and spreads rapidly, many keepers place it on an isolated rock or island so it does not overgrow neighboring corals. If the polyps stay retracted for days, check flow and for irritation from neighbors.
Feeding
Photosynthetic — it meets most of its needs from light via symbiotic zooxanthellae. It benefits from, but does not require, occasional broadcast feeding of coral foods and captures fine particulate matter.
Propagation
Extremely easy to frag — simply cut or peel a section of the mat off the rock with a razor and attach it to a new plug or rock with reef glue. It quickly re-encrusts.
Full step-by-step: How to Frag Green Star Polyps (GSP)
Cautions
A fast spreader that will overgrow and shade out slower corals — give it its own space or trim it back. Otherwise peaceful and non-stinging.
Frequently Asked Questions
Is green star polyps easy to grow?
Very. It’s one of the hardiest, fastest corals, thriving in a wide range of light and flow. It’s a great beginner coral, but grows so fast it can overtake rock.
How do I keep GSP from spreading?
Keep it on an isolated island rock separated from your main aquascape, since it encrusts over everything in its path. Trimming and scraping back the purple mat controls it.
Why is my GSP staying closed?
Newly placed or disturbed GSP can sulk for days to weeks before the polyps extend. Give it stable moderate flow and light; a film-algae layer or irritation will also keep it closed.