Why does my Captain Jack Rhodactis Mushroom Coral inflate and deflate throughout the day?

Rhodactis indosinensis regulates water content to manage light and nutrient uptake. In brighter zones it may flatten to shed light; in lower light or higher nutrients it may balloon. Occasional deflation is normal, but persistent collapse suggests irritation, excessive flow, or unstable alkalinity. Check for nearby stingers, reduce direct laminar flow, confirm alk 8–9 dKH, and run fresh carbon to remove irritants.

How can I keep its blues and greens from browning out over time?

This species hails from turbid, nutrient-moderate lagoons, so it colors best under blue-heavy spectrum with moderate PAR (60–120). Maintain low but detectable nutrients (NO3 5–15 ppm, PO4 0.03–0.08), avoid white-heavy lighting, and keep iron/iodine within normal reef ranges via regular water changes. If it browns, reduce intensity 15–20%, increase blue channels, and stabilize nutrients for 2–3 weeks before reassessing.

My Rhodactis is shadowing nearby zoas. How do I control spread without hurting the colony?

Isolate it on its own “island” rock with a sand moat, then trim the mat edge with a scalpel. Any fragments can regrow, so remove loose pieces with tweezers and place them in a frag cup. If it’s already encroaching, gently peel the foot during a deflation cycle. Maintain moderate, indirect flow so detached pieces don’t raft into other corals.

It looks healthy but refuses food—should I worry?

Many Rhodactis meet most energy needs via symbionts and dissolved organics. If parameters are stable and growth continues, refusal isn’t a problem. Try tiny, occasional offerings of mysis or pellet dust at dusk with pumps off; avoid oversized food that triggers a “spit out.” If it consistently rejects food and shrinks, test for salinity drift, high phosphate binding (from media), or bacterial stress and adjust.

TSA Captain Jack Rhodactis Mushroom Coral

Mushrooms Soft Coral

Overview

Captain Jack Rhodactis Mushroom Coral shows broad, textured oral discs with short, knobby vesicles. Rhodactis indosinensis is a soft, mushroom-type corallimorph that prefers low to moderate light and gentle to moderate, indirect flow. It is photosynthetic via symbiotic algae but will accept small meaty foods, which can speed growth and deepen coloration. Place on rock with space around it, as it can expand and irritate nearby corals when touched or shaded.

Quick Facts

Care Easy

Lighting Low–Moderate

Flow Low–Moderate

Placement Low–Mid

Temperament Semi-aggressive (keep 3–6 inches spacing)

Recommended Parameters

Temp 76–80°F

pH 8.1–8.4

Salinity 1.025–1.026

Calcium 380–430 ppm

AlkAlkalinity 8–10 dKH

Magnesium 1250–1350 ppm

Feeding photosynthetic, mysis shrimp, brine shrimp, finely chopped seafood (shrimp, krill, fish), zooplankton, microplankton/marine snow, coral-specific powdered foods

Care & Placement

Captain Jack Rhodactis Mushroom Coral (Rhodactis indosinensis) thrives in stable, nutrient-moderate systems. Provide low to moderate light (PAR ~50–100) and gentle, indirect flow to keep detritus from settling without lifting the polyp. Place low to mid in the tank on rubble or a shaded rock ledge; allow 3–4 inches of space as it can spread and irritate neighbors with mucus and overgrowth. Temperament is semi-aggressive by contact, so keep away from prized SPS/LPS and stinging anemones. Feed 1–2 times weekly with small mysis, finely chopped seafood, or coral foods; target feed lightly and turn down flow during feeding. Avoid heavy feeding that can foul water.Maintain 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 2–15 ppm, phosphate 0.03–0.08 ppm. Test weekly with reliable kits, use a refractometer for salinity, and keep swings minimal. Drip acclimate 30–45 minutes, then light-acclimate in shade for 1–2 weeks. If it bleaches or looks washed out, reduce light and improve stability; if it stretches or collects debris, increase gentle flow. Gaping mouth, persistent shrinking, or tissue recession often signal parameter swings—correct, perform a partial water change, and move to lower light/flow. Dip new specimens, avoid gluing the foot directly, and let it attach to rubble in a container before placing. Regularly siphon detritus around the base to prevent irritation.

FAQ

Frequently Asked Questions

About the TSA Captain Jack Rhodactis Mushroom Coral

Why does my Captain Jack Rhodactis Mushroom Coral inflate and deflate throughout the day?

Rhodactis indosinensis regulates water content to manage light and nutrient uptake. In brighter zones it may flatten to shed light; in lower light or higher nutrients it may balloon. Occasional deflation is normal, but persistent collapse suggests irritation, excessive flow, or unstable alkalinity. Check for nearby stingers, reduce direct laminar flow, confirm alk 8–9 dKH, and run fresh carbon to remove irritants.
How can I keep its blues and greens from browning out over time?

This species hails from turbid, nutrient-moderate lagoons, so it colors best under blue-heavy spectrum with moderate PAR (60–120). Maintain low but detectable nutrients (NO3 5–15 ppm, PO4 0.03–0.08), avoid white-heavy lighting, and keep iron/iodine within normal reef ranges via regular water changes. If it browns, reduce intensity 15–20%, increase blue channels, and stabilize nutrients for 2–3 weeks before reassessing.
My Rhodactis is shadowing nearby zoas. How do I control spread without hurting the colony?

Isolate it on its own “island” rock with a sand moat, then trim the mat edge with a scalpel. Any fragments can regrow, so remove loose pieces with tweezers and place them in a frag cup. If it’s already encroaching, gently peel the foot during a deflation cycle. Maintain moderate, indirect flow so detached pieces don’t raft into other corals.
It looks healthy but refuses food—should I worry?

Many Rhodactis meet most energy needs via symbionts and dissolved organics. If parameters are stable and growth continues, refusal isn’t a problem. Try tiny, occasional offerings of mysis or pellet dust at dusk with pumps off; avoid oversized food that triggers a “spit out.” If it consistently rejects food and shrinks, test for salinity drift, high phosphate binding (from media), or bacterial stress and adjust.