Crystal Hard Coral Galaxea Sp

Description

Crystal Hard Coral (Galaxea sp.)

(Also known as Crystal Galaxy Coral, Starburst Coral, or Tooth Coral)

Overview

The Crystal Hard Coral (Galaxea sp.) is a striking large-polyp stony (LPS) coral recognised for its dense clusters of small, star-shaped polyps and crystal-like appearance. Each polyp sits atop a pointed skeletal ridge, giving colonies a unique, glittering texture under aquarium lighting. Colours range from vivid green and turquoise to brown, purple, or cream, often glowing intensely under actinic or blue LED light. Fast-growing and hardy, Galaxea is a rewarding coral for intermediate reef keepers — though its long sweeper tentacles demand careful placement.

Origin

Distributed widely throughout the Indo-Pacific, including Indonesia, Fiji, the Solomon Islands, and the Great Barrier Reef. Found in shallow reef slopes and lagoons with moderate light and strong, alternating current.

Feeding

The Crystal Hard Coral is photosynthetic, containing zooxanthellae that provide most of its nutritional needs. However, it benefits greatly from supplemental feeding to enhance colour and growth:

• Mysis shrimp and finely chopped meaty foods

• Planktonic coral foods or marine snow

• Phytoplankton and microplankton blends

Feed 1–2 times per week, especially at night when tentacles are extended.

Lighting

Moderate to high lighting. Provide bright, full-spectrum light from LED, T5, or metal halide systems to support photosynthesis and vivid coloration.

• PAR levels of 150‚Äì250 ¬µmol/m¬≤/s are ideal.

• Gradually acclimate to high light to avoid bleaching.

Water Flow

Moderate, variable flow. Gentle turbulence keeps the polyps clean and extended while delivering food and oxygen. Avoid strong, direct jets that may damage the delicate polyp tissue or cause retraction.

Placement

• Position in the mid to lower levels of the tank, on rockwork or sandy substrate, where flow passes evenly.

• Allow at least 15‚Äì20 cm (6‚Äì8 inches) of space around the coral ‚Äî Galaxea extends long, stinging sweeper tentacles (up to 15 cm / 6 inches) at night that can damage nearby corals.

• Secure colonies firmly to prevent shifting.

Tank Mates

Reef safe with caution. Compatible with:

• All reef-safe fish (clownfish, gobies, tangs, etc.)

• Snails, shrimp, and other invertebrates

• LPS and soft corals placed at a safe distance

Avoid:

• Aggressive or large-polyped corals within reach of its sweepers (Euphyllia, Acanthastrea, etc.)

• Butterflies, angelfish, and puffers that may nip coral tissue

Aggression

Highly aggressive. Galaxea corals possess long, potent sweeper tentacles used for defense and territory. These can sting and kill nearby coral tissue, even from a distance. Always provide generous spacing in mixed reefs.

Experience Level

Intermediate. Galaxea is hardy and adaptable but requires thoughtful placement, consistent water quality, and awareness of its aggression potential. Suitable for aquarists with basic LPS experience.

Water Parameters

• Temperature: 24‚Äì27¬∞C (75‚Äì81¬∞F)

• pH: 8.1‚Äì8.4

• Salinity: 1.024‚Äì1.026 SG

• Hardness (dKH): 8‚Äì12

• Calcium: 400‚Äì450 ppm

• Magnesium: 1250‚Äì1350 ppm

• Nitrate: <10 ppm

• Tank Size: Minimum 75 gallons (280L) for stability and spacing

Maintain high water quality and stable alkalinity for steady skeletal growth. Protein skimming and regular water changes help control organics.

Reef Compatibility

Reef safe with caution. A visually stunning LPS coral for display tanks, but best placed alone or at the edge of rockwork to prevent conflict. Under blue lighting, its polyps glow intensely, making it a favourite for creating dramatic nighttime reef visuals.