Plate Coral

Fungia spp.

The solitary plate coral that slowly moves around the sand — hardy, but keep it off sharp rock.

Difficulty: Beginner–IntermediateLPS coral

The plate coral (Fungia spp.) is a reef oddity in the best way — a single, free-living disc coral that isn't glued to anything and can slowly inflate, deflate and even "walk" across the sand to find the spot it likes. It's a hardy, beginner-friendly LPS with one firm rule: it lives on the SAND, because sharp rock damages its soft underside.

Good to know: Place on SAND (not rock — sharp edges cut its underside); it can move and inflate.

📊 What keepers actually ask: Loved for its "walking"; the recurring mistakes are placing it on rock (damages its underside) and crowding it (it moves and stings).

Care at a glance

Colony / form	A single free-living disc (not colonial); can inflate and slowly move itself.
Lighting	Low to moderate — around 50–150 PAR.
Water flow	Low to moderate, indirect — gentle enough to let it inflate.
Placement	On the SAND BED, with open space around it — it will move to its preferred spot, and it can sting (or be stung by) close neighbours.
Temperature	75–82°F (24–28°C).
pH	8.1–8.4.
Specific gravity	1.023–1.026 (reef-standard ≈35 ppt).
Other targets	LPS build a stony skeleton — keep alkalinity (≈8–11 dKH), calcium (≈400–450 ppm) and magnesium (≈1300–1450 ppm) stable.
Feeding	Photosynthetic PLUS meaty foods once or twice a week (it extends feeding tentacles, usually at night).
Growth & spread	Slow; stays a single disc that grows larger over time.
Natural range	Indo-Pacific.

Beginner-friendly, done right. A hardy, characterful LPS that behaves like no other coral — it's free-living (unattached), it inflates and deflates, and it can slowly "walk" across the sand to reposition itself. The rules are simple: keep it on the SAND (rock edges cut its soft underside and it can't sit right), give it low-to-moderate light and gentle flow so it can inflate, and leave open space around it (it can sting neighbours, and its wandering can bump them). Feed it a meaty morsel once or twice a week. Stable alk/Ca/Mg like any LPS.

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.

"Corals don't move." Fungia does — it's free-living and can slowly inflate and walk across the sand to find better light or flow. That's normal, healthy behaviour.
"Put it on the rockwork like other corals." No — a plate coral belongs on the sand; sharp rock damages its soft underside and it can't sit properly.

Before you buy

A sand bed with open space (it moves and can sting neighbours).
Low-to-moderate light and gentle flow so it inflates.
Stable alk/Ca/Mg; meaty foods to feed it.

Signs something's wrong

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

Staying deflated or not inflating — flow too strong, a parameter issue, or damage to the underside from rock.
A bare or receding patch, especially on the underside — often rock damage or an infection; move it to clean sand.
Brown-jelly-like slime or rapid tissue loss — an emergency; remove affected tissue and improve water.

Never

Never keep it on rock — it needs sand.
Never crowd it against other corals — it moves and stings.
Never blast it with strong flow — it won't inflate.

Common plate coral questions

Can plate corals really move?

Yes — Fungia are free-living corals that aren't attached to anything, and they can slowly inflate, deflate and "walk" across the sand to reach light or flow they prefer. It's completely normal behaviour.

Where should I place a plate coral?

On the sand bed, not on rock — its soft underside is easily cut by sharp rock, and its rounded skeleton is made to sit in soft substrate. Give it open space, since it moves and can sting close neighbours.

Is the plate coral peaceful?

It won't harm fish, but it has stinging tentacles and it wanders, so it can sting or bump corals it reaches — leave open space around it.

Do plate corals need feeding?

They're largely photosynthetic but respond well to meaty foods once or twice a week, extending feeding tentacles (usually at night). Feeding supports growth and health.

Is the plate coral a good beginner coral?

Yes — it's a hardy, forgiving LPS, as long as you keep it on the sand, give it gentle flow and moderate light, leave it space, and hold your parameters stable.

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:

Saltwater Aquarium Blog — Plate Coral Care Guide — sand placement, movement, feeding
Extreme Corals — Fungia Plate Coral Care Guide — light, flow, placement
metareef — Plate Coral Care — PAR, flow, placement, feeding

Written and fact-checked by The Coralkin Team against marine-aquarist sources — if your plate 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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