Why does my Goldilocks Gumdrop (Acropora tenuis) shift from multicolor to uniform brown or neon green?

This species is sensitive to light spectrum and nutrient balance. A richer blue/UV spectrum (400–470 nm) and moderate PAR (250–350) help maintain multitone tips and contrasting polyps. Too little light or excess nutrients push brown/green pigments; too much light with ultra-low nutrients can wash colors. Aim for NO3 5–15 ppm, PO4 0.03–0.1 mg/L, alk 8–9 dKH, and stable temp.

What flow pattern promotes the best branch density without burning the tips?

Use strong, chaotic flow that alternates direction to flush the corallites, not a constant laminar blast. Position pumps for intersecting gyres and random pulses so polyps extend fully but tissue doesn’t recede at axial tips. If tips look glossy or receding, reduce direct velocity or adjust angle; if detritus settles between branches, increase turbulence.

Are there species-specific pests or symbionts I should watch for?

Acropora-eating flatworms and “red bugs” target A. tenuis readily. Inspect for bite marks or pale patches between corallites. Dip new pieces and consider periodic low-stress dips if symptoms appear. Tiny guard crabs (Tetralia/Trapezia) often shelter in branches and can boost polyp health and polyp cleaning; avoid dipping them out unless necessary.

How do I prevent shadowed bases and dead zones in a maturing colony?

Tenuis builds dense radial corallites that shade lower tissue. Use multi-angle lighting, rotate the colony monthly, and prune interior branches lightly to open channels. Mount higher with space around the base and keep nearby fleshy LPS at a distance to avoid stings. Occasional amino/particulate feeds at night can support shaded tissue under strong flow.

TSA Goldilocks Gumdrop Acropora Coral

Acropora SPS

Overview

Goldilocks Gumdrop Acropora Coral shows bushy branching with rounded, bead-like corallites. Acropora tenuis is a small-polyp stony branching coral that prefers strong light and high, turbulent water flow. It is primarily photosynthetic with symbiotic algae but will accept very fine planktonic foods, which can support growth and color. Place high on stable rockwork with room for upward growth, away from aggressive stingers, and avoid rapid changes in alkalinity or temperature.

Quick Facts

Care Difficult

Lighting High

Flow High

Placement High

Temperament Semi-aggressive (short sweepers; 2–3 inches spacing)

Recommended Parameters

Temp 77–80°F

pH 8.1–8.4

Salinity 1.025–1.026

Calcium 420–450 ppm

AlkAlkalinity 7–9 dKH

Magnesium 1280–1350 ppm

Feeding photosynthetic (primary), microplankton, rotifers, copepod nauplii, reef roids, oyster eggs, amino acid supplements, coral-specific powdered foods

Care & Placement

Goldilocks Gumdrop Acropora Coral (Acropora tenuis) prefers strong, stable conditions. Provide 250–350 PAR with a blue-heavy spectrum; acclimate to light by starting lower or reducing intensity, then ramp up over 1–2 weeks to avoid bleaching. Aim for strong, random flow to keep polyps active and prevent detritus buildup; avoid direct, laminar jets that can damage tissue. Maintain temperature 75–79°F (24–26°C), salinity 1.025–1.026, pH 8.1–8.4, calcium 420–460 ppm, alkalinity 7.5–9 dKH, magnesium 1300–1400 ppm, nitrate 2–10 ppm, and phosphate 0.03–0.08 ppm. This species is sensitive to swings, especially in alkalinity; dose consistently and use an auto top-off to keep salinity steady. Feed lightly 1–3 times weekly with fine zooplankton or amino acids to support color and growth without spiking nutrients.Place frags high in the tank on solid rock with epoxy or super glue gel, in strong, turbulent flow. Give at least 3–4 inches of space from neighbors; it is generally peaceful but can suffer from contact stings and will overgrow nearby small-polyp stony corals if crowded. Avoid proximity to long-sweeper LPS. Dip and quarantine new pieces to exclude pests like flatworms or red bugs. Monitor with reliable test kits; log results and watch for trends. Pale tips or overall lightening suggest too much light or too little nutrients; browning points to low light or elevated nutrients; rapid tissue recession often follows alkalinity swings or pest damage. If stress appears, reduce light, increase flow slightly, correct parameters slowly, and verify stability before making further changes.

FAQ

Frequently Asked Questions

About the TSA Goldilocks Gumdrop Acropora Coral

Why does my Goldilocks Gumdrop (Acropora tenuis) shift from multicolor to uniform brown or neon green?

This species is sensitive to light spectrum and nutrient balance. A richer blue/UV spectrum (400–470 nm) and moderate PAR (250–350) help maintain multitone tips and contrasting polyps. Too little light or excess nutrients push brown/green pigments; too much light with ultra-low nutrients can wash colors. Aim for NO3 5–15 ppm, PO4 0.03–0.1 mg/L, alk 8–9 dKH, and stable temp.
What flow pattern promotes the best branch density without burning the tips?

Use strong, chaotic flow that alternates direction to flush the corallites, not a constant laminar blast. Position pumps for intersecting gyres and random pulses so polyps extend fully but tissue doesn’t recede at axial tips. If tips look glossy or receding, reduce direct velocity or adjust angle; if detritus settles between branches, increase turbulence.
Are there species-specific pests or symbionts I should watch for?

Acropora-eating flatworms and “red bugs” target A. tenuis readily. Inspect for bite marks or pale patches between corallites. Dip new pieces and consider periodic low-stress dips if symptoms appear. Tiny guard crabs (Tetralia/Trapezia) often shelter in branches and can boost polyp health and polyp cleaning; avoid dipping them out unless necessary.
How do I prevent shadowed bases and dead zones in a maturing colony?

Tenuis builds dense radial corallites that shade lower tissue. Use multi-angle lighting, rotate the colony monthly, and prune interior branches lightly to open channels. Mount higher with space around the base and keep nearby fleshy LPS at a distance to avoid stings. Occasional amino/particulate feeds at night can support shaded tissue under strong flow.