Reefara › Troubleshooting

Coral Polyps Won't Open? Here's Why (And How to Fix It)

Closed polyps for more than 24 hours means something changed. Here's how to figure out what, and fix it before it gets worse.

Reefara is a reef-keeping reference site covering tank setup, equipment selection, water chemistry, livestock care, and troubleshooting. Whether you are planning your first nano reef or upgrading to a 200-gallon mixed reef, our guides, calculators, and species encyclopedia are here to help you make better decisions.

Browse the beginner's path if you are new, the buyer's guides for equipment recommendations, the species encyclopedia for livestock, the reef tools for calculators and planners, and the troubleshooting hub when something needs fixing.

All equipment recommendations are based on tested products and real-world hobbyist feedback. Affiliate relationships are disclosed on every applicable page.