About Royal Gramma

Gramma loreto is found in the Caribbean, where it lives in cave overhangs and ledge undersides. In the aquarium, Royal Grammas adopt the same behavior: they hover near rockwork, often upside-down under overhangs, darting to catch food and retreating to their territory. The split coloration - purple anterior, yellow posterior - is unique among common reef fish.

Care parameters

Tank size
30 gal+
Adult size
3 in
Diet
Carnivore
Reef-safe
Yes
Temperament
Peaceful
Difficulty
Beginner

Tank setup

Royal Grammas thrive with rockwork that includes overhangs and caves. Provide at least one cave the fish can claim as territory. Lighting can be standard reef, no special requirements. Salinity 1.024-1.026, pH 8.1-8.4, standard reef temps.

Diet

Accept frozen mysis, frozen brine, prepared pellets, and most reef foods readily. No special feeding requirements. Captive-bred specimens (Sea & Reef, ORA) are particularly easy to wean to dry foods.

Compatibility

Royal Grammas are mostly peaceful. They will defend their cave from other small territorial fish (jawfish, dottybacks, other grammas). Avoid:

  • Other Royal Grammas (territorial fights)
  • Other Gramma species (Black Cap, Brazilian Gramma) in tanks under 75 gallons
  • Aggressive dottybacks
  • Large predators (groupers, lionfish, triggers)

Excellent tankmates: clownfish, gobies, blennies, cardinalfish, peaceful wrasses (six-line is borderline - sometimes nips Royal Gramma), small tangs (in larger tanks).

Captive-bred availability

ORA and Sea & Reef captive-breed Royal Grammas. Captive-bred specimens are dramatically hardier than wild-caught and accept prepared foods immediately. Pricing $40-80 captive-bred vs $25-50 wild-caught.

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Aquarium-keeping fundamentals

Whatever specific topic brought you here, four fundamentals govern long-term aquarium success: water quality, parameter stability, biological filtration, and species-appropriate husbandry. Skip any one and the others struggle to compensate.

Water quality: ammonia + nitrite at zero, nitrate under 30 ppm freshwater + 10 ppm reef. Test weekly with API or Salifert kits. Use our water parameter checker to score your readings against your tank type.

Parameter stability: stable wrong parameters beat fluctuating ideal parameters. Most fish tolerate a wide pH range if it's stable. Sudden swings of 0.4+ pH or 5+°F kill fish faster than chronic suboptimal values. Use temperature controllers (Inkbird) + automated dosing for consistency.

Biological filtration: the bacterial colony on your filter media + rock + substrate is the engine. Never replace all media at once. Use our filter turnover calculator to size correctly.

Species-appropriate husbandry: research adult size, territoriality, diet, and tankmate compatibility before purchase. Use our tank stocking calculator + compatibility guides.

Frequently asked questions

How long does an aquarium take to set up? 4-6 weeks for full cycling + first stocking. Use our cycle ETA calculator + how long does cycling take.

What's the best aquarium for beginners? 20-gallon long. Big enough for parameter stability, small enough for budget + space. See beginner picks.

How often should I do water changes? 25-30% weekly. See water change frequency Q&A + water change calculator.

Why does my fish keep dying? 5 leading causes: uncycled tank, wrong species pairings, no quarantine, undersized tank, neglected water-change schedule. See full diagnosis.

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