Bubble Coral

Bubble coral is one of those unmistakable LPS (large polyp stony) corals that instantly draws attention. With its inflated, grape-like vesicles and gentle movement, it brings a soft, dramatic look to any reef tank. While often recommended for intermediate hobbyists, bubble coral is surprisingly forgiving if you respect its space, lighting needs, and feeding habits.

Bubble Coral Care: Placement, Flow, and Lighting

Bubble coral (most commonly Plerogyra sinuosa) prefers a calm, stable environment and can expand to several times the size of its skeleton. Planning placement from day one is critical.

Placement & Aggression

Bubble coral has long sweeper tentacles that extend at night and can sting neighboring corals. To keep the peace in your reef:

• Give at least 4–6 inches of space from other corals in all directions.
• Place it on the sand bed or a low, stable rock ledge to reduce risk of falls.
• Avoid sharp rock edges that can puncture the tissue as it inflates and deflates.

If you’re planning a mixed reef with other LPS, you might also enjoy our guide to hammer coral care for comparison on aggression and spacing.

Flow & Lighting

Bubble coral thrives under moderate PAR and gentle, indirect flow:

• Lighting: Low to moderate light (roughly 50–120 PAR). Too much light can cause the bubbles to stay shrunken and look stressed.
• Flow: Low to moderate, random flow that gently moves the bubbles without whipping or folding them over.
• Tip: If the skeleton is regularly exposed or the bubbles look deflated, consider reducing light or flow and check water parameters.

Feeding, Water Parameters, and Long-Term Health

Like many LPS corals, bubble coral contains zooxanthellae but also benefits from targeted feeding. Proper nutrition and stable water chemistry go a long way toward vibrant color and full polyp extension.

Feeding Bubble Coral

While it can survive on light alone in a nutrient-rich system, bubble coral usually responds very well to occasional meaty foods:

• Offer small pieces of mysis shrimp, finely chopped seafood, or quality LPS pellets 1–2 times per week.
• Use a turkey baster or pipette to gently place food on the oral area when the tentacles are extended.
• Turn off or reduce flow for 10–15 minutes so the coral can capture and ingest food.

For more feeding strategies across different species, check out our article on LPS coral care.

Water Parameters & Stability

Bubble coral appreciates the same stable conditions as most reef inhabitants:

• Temperature: 24–26°C (75–79°F)
• Salinity: 1.025–1.026 specific gravity
• Alkalinity: 8–9.5 dKH
• Calcium: 400–450 ppm
• Magnesium: 1250–1350 ppm
• Nitrate & Phosphate: Low but detectable; avoid ultra-sterile systems.

Hobbyist tip: Receding tissue along the skeleton edges often points to swings in alkalinity or salinity, or to direct physical damage from too much flow.

Common Problems and Simple Solutions

Most issues with bubble coral come down to placement, aggression, or sudden parameter changes.

• Receding tissue: Check for stings from nearby corals, sharp rock points, or rapid changes in alkalinity.
• Deflated bubbles: Often linked to excessive light or flow; gradually adjust both and monitor for improvement over several days.
• Brown jelly infections: Remove affected areas promptly, improve flow, and ensure stable, clean water conditions.

If you’re designing a layout that highlights your centerpiece corals, our reef aquascaping ideas article can help you plan safe, open zones for large LPS like bubble coral.

With thoughtful placement, gentle flow, moderate lighting, and occasional feeding, bubble coral can become a long-lived showpiece in your reef tank. Its unique shape and movement provide contrast to branching SPS and encrusting corals, making it a favorite for aquarists who want a dramatic yet manageable centerpiece.

Sources

• Borneman, E. H. (2001). Aquarium Corals: Selection, Husbandry, and Natural History. TFH Publications.
• Sprung, J. (2002). Corals: A Quick Reference Guide. Ricordea Publishing.
• Veron, J. E. N. (2000). Corals of the World. Australian Institute of Marine Science.
• General consensus and best practices from long-term reef aquarium hobby literature and community experience.