Sun Coral & NPS Care Guide: Tubastraea & Non-Photosynthetic Corals

1. What Is an NPS Coral?

Non-Photosynthetic (NPS) corals are corals that lack symbiotic zooxanthellae — or have so few that they cannot survive on photosynthesis alone [1]. Unlike the LPS, SPS, and soft corals that derive 80–95% of their energy from internal algae, NPS corals must capture all their food from the water column [1].

In nature, NPS corals fill specific ecological niches: caves, overhangs, vertical walls, and deep water where light is limited but plankton-rich currents flow continuously [2]. Tropical lagoons rich in stony corals are NPS-poor; the niche is reversed in shaded and turbulent zones [2].

The defining hobby challenge: NPS corals must be fed actively and often [3]. A casual approach to feeding kills them. Successful NPS keepers commit to daily or multi-daily feeding routines for the life of the coral — sometimes years of consistent daily work [4]. That commitment requirement makes NPS keeping the most demanding niche in the reef hobby alongside Goniopora at the difficult end. [5]

2. Major Sun Coral Species

A few NPS species dominate the aquarium trade [6]. Sun corals (Tubastraea family) are by far the most common; some related stony NPS appear occasionally [7]. [3]

Other commonly-traded NPS:

• Scleronephthya — the most visually spectacular NPS; bright pink, orange, or yellow tree-like soft coral [8]. Notorious difficulty.
• Dendronephthya — chain-link tree softie; extreme difficulty [9]. Most specimens die within 6 months even with dedicated tanks. [10]
• Diodogorgia — orange and yellow finger gorgonian; intermediate difficulty. [11]
• Sea fan gorgonians — Muricea, Plexaura; some are photosynthetic, many are NPS — ID carefully before buying. [12]

3. Tubastraea Deep Dive

Tubastraea is a genus of stony corals in the family Dendrophylliidae [1]. Despite being non-photosynthetic, they are LPS-style with distinct polyps and a calcium carbonate skeleton [3]. [1]

T. coccinea (Orange Sun)

The classic sun coral. Brilliant orange to red-orange polyps with golden tentacles [2]. Native to Caribbean reefs but now invasive across the tropical Atlantic and increasingly the Indo-Pacific via shipping ballast [3]. Most commonly seen in the trade.

Mature colonies form rounded clusters of 20–100 polyps [3]. Each polyp opens at night (or during feeding) to reveal a fluffy yellow-orange tentacle crown roughly 1–2 cm wide [4]. [2]

T. micranthus (Black Sun)

The dark-colored sister species. Dark green to nearly black coloration; smaller polyps than coccinea [5]. More demanding feeding requirements and slower-growing [6]. Less commonly traded but highly photogenic in dark-themed displays. [7]

T. aurea (Yellow Sun)

Bright yellow polyps and tentacles. Care is identical to coccinea, but specimens are less common in trade and command 30–50% higher pricing than orange morphs. [8]

4. Dendrophyllia & Balanophyllia

Dendrophyllia

Dendrophyllia are branching sun corals — tree-shaped colonies with polyps arranged along the branches rather than in clusters [9]. Most often appear as bright yellow to orange specimens with a distinctive branching skeleton visible between polyps [4].

Care is similar to Tubastraea but generally more demanding: more feedings per day required, more sensitive to water quality, and slower to recover from missed feedings [10]. The dramatic branching shape is the draw — a mature Dendrophyllia is one of the most spectacular display corals possible. [11]

Balanophyllia

Balanophyllia are solitary cup corals — single-polyp specimens that look like small individual cups attached to substrate [12]. Native to cooler waters (Atlantic, Mediterranean, temperate Pacific) and demanding cooler temperatures (18–23°C) than typical reef tanks [1]. They appear occasionally in specialty NPS displays. [2]

5. Why NPS Are Difficult

NPS keeping has a high failure rate among hobbyists, but the failure modes are well understood and avoidable. [3]

• Starvation — #1 cause of NPS death. Photosynthetic corals fed once a week stay alive [4]. NPS corals fed once a week starve within months. [5]
• Polyp closure — if a sun coral polyp doesn’t open, it doesn’t feed [6]. New specimens often refuse to open in unfamiliar tanks for weeks [7]. Patience and consistent feeding gestures eventually train them to open on schedule. [8]
• Tissue recession — chronic underfeeding causes gradual loss of polyp tissue [9]. Tubastraea can lose 50% of its polyps within 6 months of inadequate feeding before visible decline becomes obvious. [10]
• Water fouling — the heavy feeding required by NPS produces nutrients quickly [11]. A poorly-skimmed tank with NPS corals can develop algae problems within weeks [12]. Strong protein skimming and frequent water changes are necessary. [1]
• Light damage — NPS corals placed in high-PAR zones bleach and die [2]. They evolved in shadow.

6. Feeding — the Entire Job

What to Feed

• Frozen mysis shrimp — the standard NPS feed [3]. Each Tubastraea polyp consumes 1–2 mysis per feeding. [4]
• Frozen brine shrimp — supplemental. Smaller polyps prefer this.
• Chopped silverside — for larger Tubastraea and Dendrophyllia polyps. [5]
• Cyclops — for the smaller polyp species and during initial acclimation. [6]
• Phytoplankton — less effective for stony NPS like Tubastraea, important for soft NPS like Scleronephthya and Dendronephthya. [7]
• Live baby brine — the gold standard for spawning NPS appetite in stubborn specimens. [8]

How Often

The published recommendation is 2–4 times per day, 7 days a week [5]. In practice, twice daily (morning and evening) is the minimum for long-term Tubastraea health [9]. Soft NPS like Dendronephthya require more frequent feedings — some experienced keepers run continuous-drip feeders to deliver food every 2 hours. [10]

The Feeding Protocol

Training New Specimens to Open

New Tubastraea often refuse to open for 1–3 weeks [6]. Place the new coral in a calm, shaded zone [7]. Tap on the glass near the coral or run a chopstick gently past it at the same time each evening — the disturbance often triggers polyp extension [8]. Within 1–3 weeks, the coral associates the feeding time with food and opens on schedule. [9]

7. Placement & Lighting

NPS corals want shaded placement. Direct overhead lighting damages them.

• Shaded overhangs — place under rock structures or in caves. [10]
• Vertical glass surfaces — sun corals readily attach to vertical glass in low-light zones. [11]
• Lower 1/3 of the tank only.
• PAR target: under 50. Anything above 100 PAR damages tissue over weeks. [12]

NPS corals don’t need light to live (they have no zooxanthellae), so any visible polyp extension you observe under low light is healthy [1]. They do need the polyps fully open to feed, which depends on water quality, food signaling, and stress level — not light [2]. [2]

8. Flow

NPS corals want steady, moderate flow — enough to deliver food and clear debris, not enough to fold the polyps closed. [3]

• Steady indirect flow during feeding is critical.
• Random pulse modes work well for most Tubastraea. [4]
• Avoid direct laminar blast onto the polyps.
• Important: Flow must be OFF during feeding so food settles on the polyps [5]. Set up tank flow patterns that allow easy temporary shutoff. [6]

9. The Dedicated NPS Tank

Many serious NPS keepers run dedicated tanks separate from their photosynthetic display [7]. The reasoning: NPS feeding produces high nutrient loads that conflict with the ultra-low-nutrient conditions that SPS prefers [6].

Dedicated NPS Tank Design

• Lighting: Minimal — basic LED at 20–40% intensity [8]. Just enough to see the coral.
• Skimming: Aggressive. Oversized protein skimmer to handle the high nutrient load from constant feeding. [9]
• Filtration: Often includes a refugium or skimmer + carbon + GFO [10]. Mechanical filtration runs continuously.
• Flow: Random pulse modes; ability to switch off for feeding. [11]
• Continuous feeders — many NPS keepers run automated drip feeders that release food every 2–4 hours. [12]
• Water changes: Larger than typical — 20–30% weekly to keep nutrients in check. [1]
• Inhabitants: NPS corals only; sometimes paired with hermit crabs and snails to clean uneaten food. [2]

The dedicated NPS tank approach has the highest long-term success rate [3]. Mixed display tanks can house Tubastraea well, but Dendronephthya, Scleronephthya, and other delicate NPS soft corals genuinely require dedicated conditions. [4]

10. The Sun Coral Nudibranch

Identification

• Tiny (3–8 mm) bright orange nudibranch with darker rhinophores [5]
• Color matches sun coral perfectly — effectively camouflaged [6]
• Lays small white egg ribbons on or near the coral base [7]
• Reproduces rapidly under aquarium conditions

Damage

Sun coral nudibranchs consume coral tissue from the polyps outward [8]. Affected polyps stop opening, then progressively retract [9]. Heavy infestations can kill a Tubastraea colony within 1–2 months [10]. Visual signs: polyps not opening despite consistent feeding, small white egg ribbons on the coral base, tissue recession at polyp edges. [11]

Treatment

• Manual removal — remove visible adults with tweezers in a separate container of tank water. [12]
• Bayer dip — 10-minute Bayer Advanced dip kills adults [1]. Eggs often survive — repeat dipping every 4–7 days for 4–6 weeks to catch each generation. [2]
• Quarantine — isolate affected sun corals in a quarantine tank during the 4–6 week treatment window. [3]
• Prevention: dip every new Tubastraea before adding to the display. [4]

11. Fragging Sun Corals

Tubastraea propagation is straightforward despite the genus’s feeding requirements [5]. See the complete fragging guide for tools. [6]

Tubastraea (Cluster Form)

12. Where to Buy

AllCorals tracks sun coral listings from Thai reef shops, when available: [2]

• Tubastraea (sun coral) listings
• Dendrophyllia (branching sun) listings
• All sun coral listings

NPS corals appear less frequently in the Thai market than LPS or SPS [3]. For broader context, see the Euphyllia care guide for the LPS workflow, the coral feeding guide for general feeding technique, and the coral disease guide for troubleshooting failures. [4]

13. Frequently Asked Questions

References

1. Advanced Aquarist — Non-Photosynthetic Coral Biology
2. Corals of the World — Family Dendrophylliidae
3. Tidal Gardens — Tubastraea Sun Coral Care Guide [6]
4. Reef Builders — Dendrophyllia Coral Care
5. Reef2Reef — NPS Coral Feeding Protocols
6. Reefs.com — Dedicated NPS Tank Design
7. Reefkeeping Magazine — Phestilla melanobrachia sun coral nudibranch [7]
8. Saltwater Aquarium Blog — Sun Coral Care
9. Bulk Reef Supply — Non-Photosynthetic Corals Guide
10. Reef Chasers — Sun Coral Care
11. Melev’s Reef — Sun Coral Long-term Care Notes [8]
12. CoralRx — Coral Dipping Guide (sun coral nudibranch treatment) [9]