Tank Setup
- Tank size: 20 gallons minimum
- Rock work: Essential — royal grammas are cave dwellers. They spend much of their time hovering near or inside small caves and overhangs, often swimming upside down along the ceiling of their cave.
- Multiple hiding spots: Provide at least 2–3 cave options
Water Parameters
- Temperature: 75–80°F
- pH: 8.1–8.4
- Salinity: 1.024–1.026 SG
- Ammonia/Nitrite: 0 ppm
Behavior
Royal grammas are territorial about their chosen cave but otherwise peaceful. They have the unique habit of swimming upside down along the underside of rock overhangs — this is completely normal cave-dwelling behavior, not a sign of illness. They are hardy and resistant to most common marine diseases.
Tank Mates
Excellent reef community fish. Compatible with clownfish, firefish, blennies, cardinalfish, and most peaceful marine species. Avoid keeping two royal grammas together unless in a very large tank (75+ gallons) — they are territorial toward their own species.
Frequently Asked Questions
Why does my royal gramma swim upside down?
This is completely normal. Royal grammas naturally swim along the undersides of rock overhangs in their caves. It's not a sign of swim bladder disease.
Is the royal gramma reef safe?
Yes. Completely reef safe — will not harm corals, anemones, or invertebrates.