Maricultured SPS are grown in shallow ocean water under full sun, so the shock on arrival is rarely light intensity — it is the swing in temperature, pH and oxygen that builds up inside a shipping bag over a long flight.
Hour zero: float, do not rush
Float the sealed bags for 20 minutes to equalise temperature. Open them in dim light. Bag water carries high CO2 and low pH; the moment it hits air, pH climbs and ammonia turns toxic, so do not drip-acclimate stony corals for an hour — get them out within ten minutes.
Day one
- Dip for parasites and pests following your usual protocol.
- Place low in the tank, moderate flow, roughly 30% of your normal light intensity.
- Leave them alone. No fragging, no repositioning.
Days two and three
Raise light in two steps back to full intensity and move colonies to their final position. Colour usually pales for a week before pigment returns — that is normal photoacclimation, not tissue loss.
What trouble looks like
Recession starting at the base points to handling damage or a pest; bleaching from the tips outward points to light moved too fast. Both are recoverable if you catch them in the first week.