Mushroom Coral

Discosoma / Rhodactis spp.

Bulletproof beginner coral — happy in low light and low flow, and it spreads for free.

Difficulty: BeginnerSoft coral (beginner)

Mushroom corals (Discosoma and Rhodactis “mushrooms”) are among the most bulletproof corals in the hobby — they thrive in low light and low flow, shrug off imperfect water, and multiply on their own. If you want a coral that survives a beginner's learning curve, this is it.

📊 What keepers actually ask: New reefers often ask “what coral can I NOT kill?” — mushrooms are the honest answer, as long as you keep the light and flow low.

Care at a glance

Colony / form	Flat discs that spread into a group as they split; can detach and relocate themselves.
Lighting	Low — Discosoma around 30–50 PAR; Rhodactis a little brighter (≈150–250 PAR). Too much light makes them shrink.
Water flow	Low — keep it gentle (Discosoma especially want very low flow); too much stops them opening fully.
Placement	Lower rockwork or the sand bed, in calmer, shadier spots away from strong light and flow.
Temperature	75–82°F (24–28°C).
pH	8.1–8.4.
Specific gravity	1.023–1.026 (reef-standard ≈35 ppt).
Other targets	Very forgiving of nutrients and imperfect chemistry — no dosing needed. Keep it stable.
Feeding	Mostly photosynthetic; larger Rhodactis will take an occasional meaty morsel, but they don't need target feeding.
Growth & spread	Spreads on its own — Discosoma by dropping bits of its foot (pedal laceration), Rhodactis by splitting in two (fission). Easy to propagate; not aggressive.
Natural range	Indo-Pacific reefs.

Beginner-friendly, done right. If any coral is “beginner-proof,” it's the mushroom. They tolerate lower light, low flow and the parameter swings a new tank has, and they reproduce for free. The main mistakes are giving them too much light or flow (they'll shrink and hide) — err gentle on both.

Keep those numbers steady. This coral's alkalinity, calcium and magnesium only keep it safe when they're stable. If one reads low, our free reef dosing calculator works out exactly how much to add for your water volume — and splits it safely over days.

Where does it go? Light, flow and placement make or break a coral. Our free coral placement guide shows the PAR, flow and tank zone this coral wants — and what else thrives in the same spot.

The fish store gets these wrong

Common myths, kindly corrected — no shame for having believed them.

“More light = better growth.” Not for mushrooms — too much light makes them shrink and lose colour. They're low-light corals; keep them shaded.
“My mushroom moved / disappeared.” Normal — mushrooms can detach and relocate to a spot they prefer, and Discosoma spread by leaving foot-bits behind. It isn't necessarily dying.

Before you buy

Pick a low-light, low-flow spot before you buy.
Lower rockwork or the sand bed is ideal.
Expect (and welcome) it to spread on its own.

Signs something's wrong

A struggling coral is almost always telling you about light, flow or water — here's what to watch for:

Staying shrunken or curled (“clam-shelling”) — usually too much light or flow; move it lower and shadier.
Detaching and drifting — often it's seeking lower light/flow; let it settle somewhere calmer.
Losing colour or thinning — check for excess light and keep water stable.

Never

Never place mushrooms in high light or strong flow.
Never panic if one detaches and moves — it's normal.
Never chase pristine SPS-level chemistry for these — they prefer it easy.

Common mushroom coral questions

Are mushroom corals good for beginners?

They're among the best — hardy, tolerant of lower light, low flow and imperfect water, and they reproduce on their own. Just keep the light and flow gentle.

Why did my mushroom coral move or detach?

That's normal. Mushrooms can let go and relocate to a spot with light and flow they prefer, and Discosoma spread by dropping bits of their foot. A wandering mushroom usually isn't a dying one.

What lighting do mushroom corals need?

Low light — Discosoma around 30–50 PAR, Rhodactis a bit brighter (150–250 PAR). Too much light makes them shrink, so keep them shaded and low in the tank.

How do mushroom corals reproduce?

Asexually and easily — Discosoma by pedal laceration (dropping foot fragments that grow into new mushrooms), Rhodactis by splitting in two. You'll get more over time for free.

Do mushroom corals need to be fed?

Not really — they're mostly light-powered. Larger Rhodactis will take the occasional meaty bit, but target feeding isn't necessary.

Sources & further reading

This guide was written and fact-checked against these authorities. It's honest, general guidance — not a diagnosis, and not a substitute for an aquatic vet or your own test kit:

Tidal Gardens — Rhodactis Mushroom Coral Care — lighting/PAR, flow, placement, propagation
Tidal Gardens — Discosoma Mushroom Coral Care — low light/flow, pedal laceration
Saltwater Aquarium Blog — Mushroom Coral Care — beginner care, fragging

Written and fact-checked by The Coralkin Team against marine-aquarist sources — if your mushroom coral is struggling, it's almost always a light, flow or water-chemistry issue — check those first and ask an experienced reefer. We never guess a care number.

🔬 Review status: team-written and fact-checked against cited sources · not yet reviewed by a marine vet. How we research & fact-check →

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