Chalice Coral Care: Light, Color, Feeding and Why Your Chalice Doesn’t Look Like the Photo

You bought the chalice because of the photo. Neon green rim, red eyes, glowing under blue light. Three weeks later it sits in your tank looking brown and dull, and the eyes have gone orange. Nothing on the test kit is off. The coral is fine. What changed is the light. The reason is fluorescent protein, and it runs on light.

Chalice care at a glance

What	What chalices want
Light	Low. Ours grow at 50 PAR or less. Start there, and raise it slowly over three weeks only if you are chasing more color.
Spectrum	Blue-heavy, with violet and near-UV if you want red eyes to stay red
Placement	Rock or sand, flat surfaces, out of strong direct flow
Flow	Low to moderate. Enough to keep mucus and detritus moving off the surface
Feeding	Depends on the genus. Some take small foods at night. Mycedium has no tentacles and eats fine particles
Spacing	6 inches or more from anything they can reach. More for strains known for long sweepers
Temperature	Normal reef temperatures. Wild Echinophyllia aspera lives in water modeled at roughly 76–84°F
Difficulty	Easy to keep alive. Harder to keep looking like the photo

Which chalice do you have?

“Chalice” is a trade word, not a species. It covers several genera that look alike on a frag plug and behave differently once they settle in. Getting this right changes how you feed it.

The old textbook family for chalices, Pectiniidae, no longer exists. Genetic work broke it up in 2012. Echinophyllia and Oxypora moved to the family Lobophylliidae, the same family as Lobophyllia and the Australian scolys. Mycedium and Pectinia moved to Merulinidae (Budd et al. 2012), a family Huang et al. reworked again in 2014. Plenty of care guides still use the old family name. If you see Pectiniidae, you are reading old information.

Genus	How to spot it	What it means for you
Echinophyllia	Encrusting or plating, with bright “eyes” (the mouths) spaced across the surface	The classic trade chalice. Can take small foods. The red-eye strains are usually here
Oxypora	Thin plates with small holes through the skeleton	In one genetic study, several Oxypora and Echinophyllia species could not be told apart (Arrigoni et al. 2016). Care is the same
Mycedium	Plates where the mouths lean toward the edge, like little noses. No tentacles	Feeds by catching fine particles in mucus. Spot feeding mysis does little for it
Echinopora	Spiny skeleton, encrusting or branching	A lookalike sometimes sold as a chalice. It was never in the old chalice family

Trade names do not tell you the genus. Some strains, like Hollywood Stunner, get listed under different genera depending on who you ask. Look at the coral itself. On our listings we name the genus when we know it.

Why your chalice doesn’t look like the photo

Most of a chalice’s color is light the coral makes.

The glow is protein

Corals build fluorescent proteins in their tissue. These proteins absorb one color of light and give off another. Blue goes in, green or red comes out. That is why a chalice that looks dull under white light lights up under blue LEDs. Blue light is what makes that color visible.

Scientists know chalices for this too. Dronpa, a light-switchable fluorescent protein that cell biologists use around the world, was first pulled from an Echinophyllia coral (Ando et al. 2004, Science).

Light controls how much the coral makes

Corals make more of these proteins under stronger light, and blue light drives it. In one study of reef corals, green and red proteins were nearly absent in dim light and rose as the light got stronger (D’Angelo et al. 2008). Chalices were not part of that study, and light is not the only thing that drives color. Still, a chalice moved from a bright, blue farm tank into a dimmer or whiter tank will often make less color. The coral is adjusting, and it can reverse.

Why red eyes fade

Echinophyllia carries a pigment that starts out green and turns red when hit with violet and near-UV light (Bollati et al. 2022). Reefers commonly report that red eyes fade in tanks with no violet or UV LEDs. If your light has a violet channel and you run it near zero, that is the first thing to change.

That red pigment also does a job. It soaks up blue light and gives back orange-red light deeper in the tissue, where the coral’s algae can use it. In Montastraea, studied alongside Echinophyllia, it returned up to about 5% of the blue light as orange-red at the surface, and Echinophyllia gave a similar result (Bollati et al. 2022, eLife). That matters most in deeper water, and chalices range into it. Echinophyllia aspera has been recorded from the surface down to roughly 200 feet, and Mycedium from about 20 to 230 feet.

When brighter means stressed

Not every glow is good news. A stressed coral that is starting to lose its algae can push out extra fluorescent protein and look brighter than ever for a short time. Researchers call this “colorful bleaching” (Bollati et al. 2020). If a chalice gets more neon over a few weeks after a temperature spike, and the brown base color is thinning out, treat it as a heat-stress warning.

Light and placement

Look at ten chalice care guides and you will find light advice from 30 PAR to 250 PAR. That spread is real information. Chalices live across a huge depth range, so they tolerate a wide band of light. Where you put yours inside that band decides its color more than its survival.

On our farm, chalices grow at 50 PAR or less. That is the low end of the range, and it is where we would start yours.

Where to measure

A PAR number only means something at the spot where the coral sits. Measure at the top surface of the coral, not at the top of the rock and not at the waterline. Two inches can change the reading a lot under a focused LED.

No PAR meter? We rent one from the store in Key West: $75 for two days with a $500 refundable deposit. One afternoon of readings shows where your bright and dim spots are.

A three-week move-in plan

Week	Where the coral sits	What you are watching for
1	Low in the tank, on the sand or a low rock, out of direct flow	Tissue staying full, mucus clearing, eyes showing
2	Move up a few inches if week one looked good	No pale patches on the side facing the light
3	Its final spot	Color starting to come back under your spectrum

If it pales at any step, go back down one step and wait another week.

Flow you can see

You do not need a flow number. Watch the coral. Good flow keeps detritus and old mucus sliding off the surface and does not fold the tissue or push it flat. If waste settles in the dips of the plate, raise the flow a little. If you see bare skeleton showing at the edges where the current hits, lower it or turn the coral.

Feeding by genus

This is where most guides go wrong. They tell you to spot feed mysis to “your chalice,” as if all chalices eat the same way.

Mycedium has no tentacles. It feeds by coating its surface in mucus, catching fine particles that drift onto it, and moving them to the mouth. A study of Mycedium elephantotus found it can tell food from mineral grains and ignores the grains (Schlichter and Brendelberger 1998). The same study found its skeleton building stayed nearly the same from about 15 to 130 feet deep, even with far less light at depth. The researchers suggest that particle feeding makes up the difference. So for a Mycedium, fine, slow-sinking foods spread over the coral work. A chunk of mysis will just slide off.

Echinophyllia and Oxypora put out small feeding tentacles, mostly after the lights go off. They can take small foods placed right on the eyes. Feed small and feed often rather than big and rarely. What does not get eaten turns into nitrate and phosphate.

Whichever you have, keep the water from getting too clean. Chalices pull nutrition from the water as well as from light. A tank stripped to zero nitrate and phosphate leaves them with less to work with. Our guide to feeding a reef tank and the one on spot feeding corals go into the how.

Spacing and aggression

Chalices fight with two weapons. The first is sweeper tentacles, long stinging tentacles that some strains send out at night. Keepers have reported Hollywood Stunner sweepers longer than 6 inches. The second is mesenterial filaments, which the coral pushes out of its mouth to digest whatever is touching it. In Mycedium these filaments are packed with large stinging cells, even though the coral has almost no stinging cells around its mouth.

You cannot tell how aggressive a coral is from its family. A study of about 700 coral fights on the reefs of the Chagos Islands found that aggression barely tracked family or growth shape (Sheppard 1979). Space each chalice by what you know about that strain, and watch at night with a flashlight the first week to see how far it reaches.

Two chalices of different strains will often fight too. Give them 6 inches or more, and do not let them grow into each other.

How fast chalices really grow

Several care guides repeat that chalices “double every four months.” None of them give a source, and we could not find any published growth data for chalices kept in tanks.

Chalices do not grow at one rate. It depends on the genus. On our farm, Mycedium is the fast one: we can take a Mycedium frag to a small colony in about three months. Echinophyllia and Oxypora take far longer.

That difference is worth knowing before you buy. If you want a chalice that fills in a spot quickly, start with a Mycedium. If you want the classic red-eyed Echinophyllia look, plan on watching it for a long time before it covers much rock.

Your first 30 days

New chalices often look worst in the first week. Shipping is dark and cold, and the coral comes out of the box tight and covered in mucus. Here is what is normal and what is not.

What you see	Normal?	What to do
Coral shrunken and slimy on day one	Yes	Dip it, place it low, leave it alone
Color looks duller than the photo in week one or two	Yes	Nothing yet. This is the light adjustment above
Eyes not showing for a few days	Usually	Keep flow gentle, lights at their normal level
Bare white skeleton at one edge that grows a little each day	No	Recession. Check parameters, move it lower, check for anything stinging it
Brown, jelly-like tissue peeling off	No	Act the same day. Remove the coral and dip it
Coral suddenly brighter than ever while the base color thins	No	Possible colorful bleaching. Lower the light and check temperature

Our guides on new corals not opening after shipping, dipping corals and telling bleaching from STN and RTN cover these in more detail.

Troubleshooting

It is turning brown

Usually light. Brown is the coral’s algae, and more of it means the coral wants more food from photosynthesis. That happens when the light is weaker than what it grew under, or when nutrients run high. Check the spectrum before you move it up.

It is losing tissue at the edges

Look for something touching it first: a neighbor’s sweeper, a snail, a frag that fell over. Then check alkalinity swings and flow hitting that edge. The water parameters guide lists the numbers that matter.

Is something eating it?

We know of no pest that targets chalices the way red bugs target Acropora or nudibranchs target montis. If you see damage that looks like bites, check for fish that pick at LPS first. Our article on fish that will eat your corals has the list.

Common questions

Are chalices good for beginners?

They are easy to keep alive and slow to show problems. The hard part is the color, and that is a lighting question more than a skill question.

What is the “eye”?

The eye is the mouth of each polyp, the center of each little cup in the skeleton. On the prized strains the eyes are a different color from the rim, which is where names like Mummy Eye come from.

Can two chalices touch?

Not safely. Different strains will sting each other. Pieces of the same colony can sit close, but give different strains 6 inches or more.

Why are some chalices so expensive?

Color, demand and growth rate. The named strains with strong eye contrast are mostly the slow-growing Echinophyllia and Oxypora, and every frag comes off a mother colony that has to grow back before it can be cut again.

Are chalices endangered?

Two species often sold as chalices, Echinophyllia aspera and Mycedium elephantotus, are both listed as Least Concern by the IUCN. Buying aquacultured still means no wild colony was taken.

Chalices we have right now

Every piece below is in our Key West systems now. See the full chalice collection for everything in stock today.

Sources

• Ando R. et al. 2004. Science 306:1370 (Dronpa, from Echinophyllia).
• Bollati E. et al. 2020. Current Biology 30(13):2433 (colorful bleaching).
• Bollati E. et al. 2022. eLife 11:e73521 (red pigment and internal light).
• Budd A.F. et al. 2012. Zoological Journal of the Linnean Society 166:465–529.
• D’Angelo C. et al. 2008. Marine Ecology Progress Series 364:97–106 (blue light and coral pigment).
• Huang D. et al. 2014. Zoological Journal of the Linnean Society 171:277–355.
• Schlichter D. and Brendelberger H. 1998. Facies (Mycedium elephantotus feeding).
• Sheppard C. 1979. Marine Ecology Progress Series 1:237 (coral aggression, Chagos).
• Arrigoni R. et al. 2016. Contributions to Zoology 85(4):387–422 (Lobophylliidae genetics).
• SeaLifeBase species summaries for Echinophyllia aspera and Mycedium elephantotus (depth, modeled temperature, IUCN status).

The Underwater Gardener grows aquacultured corals in Key West, Florida (FL Aquaculture Certificate #AQ0254072). Our corals are raised under stable reef lighting in our own systems, so they arrive already adapted to a well-run tank. Corals ship UPS Next Day Air every Tuesday and Wednesday.