Why does my Galaxy Coral (Galaxea fascicularis) send out extra-long sweepers some nights but not others?

Sweeper length varies with feeding cycles, nearby rivals, and flow. After heavy feeding or when sensing neighbors, it can push 6–12-inch sweepers. In very low flow, they travel farther and linger. Give it an “island” with 8–12 inches of buffer, maintain random, moderate–strong flow at night, and run carbon if mixing with allelopathic softies to reduce chemical triggers.

My Galaxea is receding from the edges despite stable parameters. What’s a less obvious cause?

Edge recession often ties to sediment loading and vermetid snail irritation rather than chemistry alone. Galaxea’s sharp septa trap detritus; smothering leads to slow tissue loss. Turkey-baste the colony and surrounding rock weekly, trim or control vermetids, and increase crossflow to keep pores clean. If tips are paling under high PAR, reduce intensity slightly and extend photoperiod instead.

What lighting best preserves its neon greens without washing out or browning?

Aim for moderate PAR (100–200) with strong blue/royal channels. Intense white-heavy spectra can thin tissue at the margins; overly dim or nutrient-rich setups can brown it. Balance nutrients (nitrate 5–15 ppm, phosphate 0.03–0.1 ppm), keep alk steady, and tune blues for pop while avoiding harsh hotspots. Gradually acclimate when changing LEDs or lenses.

Galaxea seems “happier” in slightly dirtier water. Is that safe long-term?

It tolerates turbid, higher-nutrient environments better than many LPS, but needs brisk, chaotic flow to prev

TSA Battlestar Galaxea Coral

Galaxea LPS

Overview

Galaxy Coral displays star-like clusters of polyps with long sweeper tentacles that extend at night. Galaxea fascicularis is a large-polyp stony coral forming encrusting to branching colonies; it prefers moderate lighting and moderate, indirect water flow. It hosts symbiotic algae for most of its energy but accepts small meaty foods or planktonic fare, which can boost growth and polyp fullness. Place it with ample space from other corals, as sweeper tentacles can sting several inches away.

Quick Facts

Care Moderate

Lighting Moderate

Flow Moderate–High

Placement Mid–Low

Temperament Highly aggressive; long sweeper tentacles (6–10 inches clearance)

Recommended Parameters

Temp 75–80°F

pH 8.1–8.4

Salinity 1.025–1.026

Calcium 400–450 ppm

AlkAlkalinity 8–10 dKH

Magnesium 1250–1350 ppm

Feeding photosynthetic (primary), mysis shrimp, enriched brine shrimp, finely chopped seafood, zooplankton, microplankton, coral-specific powdered foods

Care & Placement

Galaxy Coral (Galaxea fascicularis) does best in stable, clean water with moderate light and moderate, varied flow. Target PAR around 100–200; start low and increase over 2–3 weeks to avoid bleaching. Provide random, indirect flow strong enough to keep detritus from settling but not so strong that tissue whips against sharp skeleton. Keep temperature 24–26°C (75–79°F), salinity 1.025–1.026, pH 8.1–8.4, alkalinity 8.0–9.5 dKH, calcium 400–450 ppm, magnesium 1250–1350 ppm, nitrate 2–10 ppm, phosphate 0.02–0.08 ppm. Feed 2–3 times weekly with small meaty foods (mysis, chopped shrimp, reef roids) for faster growth and color; feed after lights dim when tentacles extend. Acclimate with a slow drip and light acclimation; stability is key, as rapid swings cause tissue recession.Place Galaxy Coral on the sandbed or low–mid rockwork with strong spacing—8–12 inches or more—from neighbors. It grows long sweeper tentacles at night that can sting and kill nearby corals; island placement helps contain aggression. Avoid contact with soft corals and most LPS; keep away from fish or inverts that nip. Watch for signs of stress: retracted polyps, pale tissue, or skeleton showing at the base. If polyps stay closed, reduce direct flow, verify alkalinity and nutrients aren’t bottomed out, and check for pests; use a coral dip if needed. Maintain regular testing, gentle turkey baster blasts to clear debris, and trim overgrown branches to prevent shading.

FAQ

Frequently Asked Questions

About the TSA Battlestar Galaxea Coral

Why does my Galaxy Coral (Galaxea fascicularis) send out extra-long sweepers some nights but not others?

Sweeper length varies with feeding cycles, nearby rivals, and flow. After heavy feeding or when sensing neighbors, it can push 6–12-inch sweepers. In very low flow, they travel farther and linger. Give it an “island” with 8–12 inches of buffer, maintain random, moderate–strong flow at night, and run carbon if mixing with allelopathic softies to reduce chemical triggers.
My Galaxea is receding from the edges despite stable parameters. What’s a less obvious cause?

Edge recession often ties to sediment loading and vermetid snail irritation rather than chemistry alone. Galaxea’s sharp septa trap detritus; smothering leads to slow tissue loss. Turkey-baste the colony and surrounding rock weekly, trim or control vermetids, and increase crossflow to keep pores clean. If tips are paling under high PAR, reduce intensity slightly and extend photoperiod instead.
What lighting best preserves its neon greens without washing out or browning?

Aim for moderate PAR (100–200) with strong blue/royal channels. Intense white-heavy spectra can thin tissue at the margins; overly dim or nutrient-rich setups can brown it. Balance nutrients (nitrate 5–15 ppm, phosphate 0.03–0.1 ppm), keep alk steady, and tune blues for pop while avoiding harsh hotspots. Gradually acclimate when changing LEDs or lenses.
Galaxea seems “happier” in slightly dirtier water. Is that safe long-term?

It tolerates turbid, higher-nutrient environments better than many LPS, but needs brisk, chaotic flow to prev