QUICK STATS

Care Level: Difficult
Coral Type: SPS
Temperament: Peaceful to Semi-Aggressive by Growth
Photosynthetic: Yes
Placement: Middle to Upper
Lighting: High
Water Flow: Strong, Random / Turbulent
Approximate Purchase Size: Varies by Frag Size
Approximate Max Size: Branching Colony Growth Depends on Stability, Space, Lighting, and Flow

CHRISTMAS ACROPORA MIRABILIS CORAL

The Christmas Acropora mirabilis Coral, often sold as Christmas Mirabilis Acropora or WWC Christmas Mirabilis Acropora, is a colorful SPS coral known for its bright green base, pink to red branch coloration, and festive high-contrast appearance. Under strong reef lighting, this coral can develop intense pink, red, green, and yellow-green tones, giving it the kind of holiday decoration energy that somehow survives year-round in a reef tank.

This Acropora variety has a branching growth form and can become a beautiful centerpiece SPS coral in mature reef aquariums. The combination of strong color, branching structure, and fine polyp extension makes it especially appealing for SPS collectors and reef keepers who enjoy corals that look incredible while quietly judging every alkalinity swing.

Like other Acropora corals, Christmas Mirabilis requires strong lighting, strong random flow, stable alkalinity, stable nutrients, and a mature aquarium. It is not a beginner coral and should not be added to unstable systems, brand-new tanks, or aquariums still going through “I changed everything this week” syndrome.

This coral is photosynthetic and receives much of its energy from reef lighting through its symbiotic zooxanthellae. It may also benefit from dissolved nutrients, amino acids, and fine particulate foods in well-managed systems. It does not have long sweeper tentacles like many LPS corals, but it can compete for space as it encrusts and branches outward.

Note: Image is a representation of what to expect. The coral you receive may vary slightly in size, branch shape, color intensity, polyp coloration, growth tips, and overall appearance.

AQUARIUM REQUIREMENTS

AQUARIUM SIZE

A minimum aquarium size of 30 gallons or larger is recommended for Christmas Acropora mirabilis, though larger mature reef systems are strongly preferred. Larger aquariums provide better parameter stability, stronger flow options, and more room for SPS growth.

Acropora corals are not usually limited by tank size alone. They are limited by stability, lighting, flow, nutrient control, and the aquarist’s ability to avoid making five changes every time one polyp looks suspicious. The coral does not need chaos. It has enough going on.

PLACEMENT RECOMMENDATIONS

Christmas Acropora mirabilis is best placed in the middle to upper areas of the aquarium where it receives high lighting and strong, random flow. Start lower or in slightly reduced light if the coral is new, freshly shipped, or coming from lower lighting, then move it gradually once it shows good polyp extension and color.

Rock Placement: Place securely on stable rockwork where the frag has room to encrust at the base and branch outward.

Sandbed Placement: Temporary sandbed placement can work during acclimation if lighting is intense, but long-term placement should usually be on rockwork with strong flow and appropriate PAR.

Spacing: Leave room around the frag for future branching growth. Acropora may not look aggressive at first, but colonies can eventually shade or crowd nearby corals.

SPS Zones: Best placed in an SPS-focused area with strong flow, stable light, and space from aggressive LPS corals. Do not place it within reach of torches, hammers, frogspawn, galaxea, chalices, or other corals with strong stings unless you enjoy turning coral placement into a crime scene.

WATER PARAMETERS

Christmas Acropora mirabilis requires clean, stable reef conditions. Stability is more important than chasing perfect numbers. Sudden swings in alkalinity, salinity, temperature, nutrients, or lighting can cause browning, bleaching, tissue recession, burnt tips, or rapid tissue loss.

Temperature: 76-79°F
pH Level: 8.1-8.4
Salinity: 1.025-1.026 specific gravity
Alkalinity: 7.5-9 dKH
Calcium: 400-450 ppm
Magnesium: 1250-1350 ppm
Nitrate: 2-10 ppm
Phosphate: 0.03-0.08 ppm

Avoid major parameter swings. Acropora can adapt to different nutrient levels, but rapid changes are often a problem. Keep alkalinity especially stable. Acros do not enjoy “surprise chemistry,” which is unfortunate because humans keep inventing it.

LIGHTING

Christmas Acropora mirabilis prefers high lighting. A general target range of 250-400 PAR works well for many Acropora corals once acclimated, though exact needs depend on the specific frag, previous lighting, nutrients, water clarity, and system stability.

LIGHTING RECOMMENDATIONS

High PAR: Place in areas with strong, stable reef lighting once acclimated.

Light Acclimation: New Acropora frags should be acclimated gradually to stronger lighting. Start lower or reduce intensity, then increase slowly over several days to weeks.

Color Display: Christmas Mirabilis may show stronger pink, red, and green coloration under higher lighting, especially when nutrients and alkalinity are stable.

Too Much Light: Signs may include bleaching, pale tissue, burnt tips, reduced polyp extension, or tissue recession.

Too Little Light: Signs may include browning, dull coloration, slow growth, weak encrusting, or loss of contrast.

Do not blast a fresh Christmas Mirabilis frag with maximum light because it looked pink in a vendor photo. That is not reef keeping. That is photon-based optimism with consequences.

WATER FLOW

Christmas Acropora mirabilis prefers strong, random, turbulent water flow. Flow should move around the coral from multiple directions rather than blasting one side constantly.

FLOW RECOMMENDATIONS

Ideal Flow: Strong, varied, random flow that keeps detritus from settling and supports gas exchange.

Avoid Direct Laminar Flow: Constant direct blasting from one direction can irritate tissue, damage growth tips, or create uneven growth.

Avoid Dead Spots: Too little flow can allow detritus to settle around branches and the base, which may contribute to tissue stress or recession.

Polyp Movement: Healthy flow should create subtle polyp movement and keep the coral surface clean without peeling tissue off the skeleton like some kind of reef-based pressure-washing tragedy.

If tissue recession begins at the base, detritus collects around the frag, or polyps stay tightly retracted, evaluate flow and placement. Acropora feedback is subtle until it suddenly is not, because apparently SPS corals prefer cliffhanger communication.

DIET

Christmas Acropora mirabilis is photosynthetic, meaning it receives much of its energy from light through its symbiotic zooxanthellae. It may also benefit from dissolved nutrients, amino acids, and fine particulate foods in the water column.

PRIMARY DIET

Photosynthesis: Strong reef lighting provides much of the coral’s energy.

Broadcast Feeding: The coral may capture fine particles from the water column during regular fish and coral feeding.

Fine Coral Foods: Amino acids, powdered coral foods, phytoplankton-style blends, and very fine suspended foods may be used carefully in established systems.

Dissolved Nutrients: Moderate detectable nitrate and phosphate can help support color and growth. Avoid stripping the aquarium too aggressively.

FEEDING FREQUENCY

Direct target feeding is usually not necessary. Broadcast feeding or general reef feeding 1-2 times per week can be beneficial if nutrients are not already high.

Avoid heavy feeding in small systems. The coral does not need a powdered-food blizzard because someone watched one SPS video and became dangerous.

COMPATIBILITY

Christmas Acropora mirabilis works well in SPS-focused and mixed reef aquariums when placed with enough room, strong lighting, strong flow, and protection from aggressive neighboring corals.

COMMON TANK MATES

Fish: Reef-safe fish such as clownfish, gobies, blennies, wrasses, tangs, cardinalfish, firefish, anthias, and other peaceful to semi-peaceful community fish.

Avoid: Fish known to nip SPS corals, such as some angelfish, butterflyfish, filefish, puffers, and certain triggers.

Invertebrates: Generally safe with cleaner shrimp, snails, hermit crabs, urchins, and most common reef invertebrates. Large urchins or bulldozing snails may move unsecured frags.

Coral: Keep away from aggressive neighboring corals, especially torches, hammers, frogspawn, galaxea, favias, chalices, acans, mushrooms, and other stinging LPS.

SPS Neighbors: Can be placed near other SPS corals with room for future growth. Watch for shading, encrusting contact, or competitive overgrowth as colonies mature.

BEHAVIORAL NOTES

Temperament: Peaceful to semi-aggressive by growth. It does not have long sweepers, but it can shade or overgrow nearby corals.

Growth Pattern: Branching Acropora with encrusting at the base before upward branch development.

Coloration: Often shows green, pink, red, and yellow-green tones. Color intensity may vary with lighting, nutrients, flow, stability, and photography conditions.

Polyp Extension: Healthy frags may show daytime or nighttime polyp extension. Reduced extension can indicate stress, pests, fish nipping, flow issues, or parameter instability.

Acropora Sensitivity: Sensitive to rapid changes in alkalinity, salinity, nutrients, temperature, and lighting.

Pest Awareness: Inspect carefully for Acropora-eating flatworms, red bugs, nudibranchs, eggs, vermetid snails, algae, and other hitchhikers before placing into the display.

Dipping: Coral dipping before introduction is strongly recommended. Use coral-safe dips according to product directions and inspect the frag plug and base closely.

Quarantine: Coral quarantine is ideal for Acropora when possible. Acro pests are not character-building. They are tiny nightmares with legs.

Frag Handling: Handle by the plug, dead skeleton, or base whenever possible. Avoid touching living tissue or fragile growth tips.

Base Encrusting: A healthy Acropora frag will usually encrust onto the plug or rock before stronger vertical growth begins.

Color Shift: Christmas Mirabilis can change appearance depending on light intensity and nutrients. Higher light may bring stronger pinks, while lower light or higher nutrients may shift the coral darker or greener.

Tank Maturity Reality: This coral should be added to a mature, stable system. A new tank with swinging parameters is not an SPS aquarium. It is a coral stress simulator.

ACCLIMATION PROCESS

This acclimation method helps reduce stress by gradually introducing the coral to your aquarium’s temperature, lighting, and water chemistry.

1. DIM THE LIGHTS

Turn down aquarium lights or place the coral in a shaded lower area at first. This helps reduce stress while the coral adjusts.

2. FLOAT THE BAG

Float the sealed bag in the aquarium for 15-20 minutes to allow the temperature in the bag to equalize with the tank.

3. OPEN BAG, ADD CORAL TO CONTAINER

Carefully open the bag and transfer the coral and shipping water into a clean container. Handle the coral by the plug, base, or dead skeleton rather than touching the living tissue or growth tips.

4. ACCLIMATE USING TANK WATER

Add small amounts of tank water to the container every few minutes for 20-30 minutes. Avoid exposing the coral tissue to air longer than necessary.

5. CORAL DIP

Use a coral-safe dip according to the product instructions. Inspect carefully for Acropora pests, eggs, algae, and hitchhikers before the coral enters your aquarium.

6. TRANSFER CORAL TO AQUARIUM

Place the coral in a lower or slightly shaded SPS-safe area at first, with strong but not harsh flow. Discard the shipping and dip water. Do not pour shipping water or dip water into your aquarium.

7. LIGHT ACCLIMATE

Allow the coral to adjust gradually over several days to weeks before moving it into brighter light. Watch for polyp extension, coloration, tissue health, and base encrusting before making major placement changes.