Pavona Coral Care: Light, Flow, ID and Leptoseris

You bought a pavona frag because the color looked good under the store lights. Three months later it has spread past the plug, thrown up a thin ridge or two, and nobody can agree whether it is a pavona, a montipora or a leptoseris. That confusion is normal. This guide sorts it out and gives you the light and flow numbers that keep it growing.

Pavona is a stony coral from the family Agariciidae, the same family as leptoseris. Reefers call it cactus coral, leaf coral or potato chip coral, depending on the shape. Most of what you see for sale grows as a crust that spreads over rock, then builds up into ridges, plates or thin upright fronds. It is one of the more forgiving stony corals, which makes it a good step up from soft corals and LPS.

Quick facts

Family	Agariciidae, about 20 recognized species
Common names	Cactus coral, leaf coral, potato chip coral
Where it comes from	Mostly Indo-Pacific reefs, from the Red Sea east into the Pacific
Light	Medium, about 100 to 200 PAR. Our WYSIWYG listing runs up to 250.
Flow	Medium, changing, enough to keep detritus off the surface
Feeding	Low. Mostly photosynthetic.
Aggression	Low. Leave 2 to 3 inches around it.
Growth	Fast for a stony coral once it settles
Care level	Easy to moderate

Growth forms: encrusting, plating, cactus

One pavona species can look completely different depending on light, flow and depth. That is part of why the names are a mess.

• Encrusting. A thin crust that spreads across rock. Most frags start this way, and our Copper Encrusting and Mint Pavonas grow like this.
• Plating and leafy. The crust lifts at the edges into thin plates or folds. Pavona plates and fronds usually carry polyps on both sides.
• Cactus. Upright, twisting fronds, each well under 1/4 inch thick. Pavona cactus is the classic. In the wild it forms thickets several feet across in calm lagoons.

Growers who sell a lot of pavona report that green types tend to plate, blue types tend to encrust and orange types go either way. Treat that as a tendency, not a rule.

One more fact worth knowing: Pavona cactus is listed as Vulnerable by the IUCN, even though it is common on many reefs. Rising sea temperatures and bleaching are the main threats.

Pavona vs montipora vs leptoseris

These three get mixed up more than any other encrusting corals, and psammocora adds to the confusion. Look at the surface up close with a flashlight and a magnifier.

Coral	Surface up close	Plates
Pavona	Shallow star-shaped polyp centers with no walls between them. Fine ridges run from one polyp to the next, so the surface looks like a net of little stars.	Thin, usually with polyps on both sides
Montipora	Very tiny polyps scattered over a surface that is often covered in small bumps or tubercles. No star pattern.	Plating types carry polyps mostly on the top side
Leptoseris	Polyps in rows with fine ridges running out from the center like pinstripes. Often strongly fluorescent.	Thin plates with polyps on the top side only
Psammocora	Very small polyps in shallow pits, fuzzy or sandy texture	Mostly encrusting or knobby

Still not sure? Our encrusting corals page shows the whole group, and the leptastrea guide covers another look-alike with larger cups.

Light and flow numbers

Our listings run pavona at medium light, 100 to 200 PAR. The WYSIWYG Copper is listed at 150 to 250. A grower with years of pavona in production aims for about 100 PAR and reports that more light does not improve the color much, while too much light bleaches it. Start a new piece near the low end and raise it over a week or two.

Flow matters more than light. The polyps sit in shallow pits between ridges, and detritus settles in them. Tissue under a film of debris dies in patches, usually starting in the low spots of a plate. Give it medium, changing flow that crosses the coral, not a single jet aimed at it. If a plate grows flat and level, it catches debris. A slight tilt helps.

Clean your pumps. Flow drops slowly as they foul, and an encrusting coral shows it in a bare patch before you notice anything else.

Color and what changes it

Wild pavona is mostly olive green or brown, the color of the algae living in its tissue. The copper, mint, purple and “freak hair” pieces in the hobby are selected color morphs. Pavona color is more stable than acropora or montipora color. Water conditions that would wash out an acropora usually do not show on a pavona.

When it does change, it is usually one of three causes: too little light (it browns), too much light or a fast increase (it goes pale), or nitrate and phosphate bottomed out (pale and thin). Our zooxanthellae guide explains why a coral browns under low light.

Feeding

Pavona gets most of what it needs from light. Our listings call it low on feeding. The polyps are small and extend mostly at night. If you want to feed, broadcast a fine food like rotifers or a reef powder once or twice a week with the pumps turned down for a few minutes, or dose amino acids lightly. Heavy feeding raises nutrients and coats the surface, which hurts more than it helps.

Growth rate and fragging

Once it settles, an encrusting pavona spreads across its plug and onto the rock in a few months. Plating and cactus forms add height as well as width. Growers describe pavona as fast for a stony coral.

The skeleton is brittle, which makes fragging easy. Snap a plate or frond with bone cutters, or cut a section off the growing edge of an encrusting piece, and glue it to a plug. Wear gloves. You can also set a plug against the growing edge and let the coral crawl onto it.

Aggression and spacing

Our listings call pavona peaceful. It has short tentacles at night, and some reefers report mild sweepers, so it is not completely harmless. Leave 2 to 3 inches around it, more from fleshy LPS like euphyllia, and keep it well away from bullies like hydnophora that will burn it. An encrusting pavona competes mostly by growing over its neighbors.

Leptoseris: the plating cousin

Leptoseris is pavona’s closest relative in the hobby. It grows as thin plates or encrusting sheets with fine pinstripe ridges, and the aquarium morphs are known for strong fluorescence.

In the wild, leptoseris is the deep-light specialist. In Hawaii, researchers using submersibles found it growing between 225 and 360 feet, where the light is less than 0.2 percent of the surface. Its thin plates grow outward instead of upward, and the fine parallel ridges on the skeleton work like little mirrors that bounce light back through the tissue until it is absorbed. Those deep colonies grew close to an inch a year at 225 feet, far faster than anyone expected.

What that means for your tank: leptoseris handles lower light than most stony corals. One grower got the best color at 75 to 125 PAR. Our listings say 100 to 200. Start it low and move it up only if the color dulls. Give it low to medium flow that keeps debris out of the folds without blasting it, because a strong jet close by kills tissue. Its sweepers can reach about an inch, so give it room.

We carry the Hulk Leptoseris and the Mr Freeze Leptoseris. See all our leptoseris.

Common problems

What you see	Likely cause	What to do
Bare or gray patches in low spots	Detritus settling on the surface	More crossing flow, clean the pumps, tilt flat plates
Pale or white all over	Too much light, or raised too fast	Move it lower or dim the light, then raise slowly
Dull brown	Too little light or high nutrients	More light, keep nitrate and phosphate low but not zero
Tissue pulling back from the edge	Alkalinity swings or contact with a neighbor	Test alkalinity, check what it touches, and move it if a neighbor is stinging it
Polyps not extending after arrival	Shipping stress	Give it a week in stable conditions before moving it

For pests that ride in on stony corals, see our coral pest guide.

Acclimation

Corals do not need a drip. Turn the lights off and float the sealed bag for 15 to 20 minutes. Open it into a clean container and add about half a cup of tank water every few minutes for 15 to 30 minutes. Lift the coral out by its plug and throw the bag water away. Dip it before it goes in the display, then place it low in the tank with the light off or low for the first day. Our acclimation and dipping guide has the details.

FAQ

The Underwater Gardener is a reef aquarium store in Key West, Florida. Quarantined: held at our Key West facility for at least 4 weeks and dipped multiple times before it’s offered for sale. Livestock ships UPS Next Day Air on Tuesdays and Wednesdays.