Bubble Coral Basics

Bubble coral (Plerogyra spp.) is a large-polyp stony (LPS) coral known for its inflated, grape-like bubbles. It’s fairly forgiving, making it a good choice for hobbyists with a bit of experience who want a showy centerpiece.

Bubble coral prefers moderate lighting and low to moderate, indirect flow. Too much flow keeps the bubbles from inflating and can damage tissue as it rubs against the skeleton.

• Placement: Bottom to mid-level, on rock with a stable base and room to expand.
• Lighting: Moderate PAR (around 75–150). Start low and slowly increase over 2–3 weeks.
• Flow: Gentle, indirect. The bubbles should sway slightly, not whip around.

Care, Feeding, and Common Mistakes

Bubble coral can live on photosynthesis alone, but regular target feeding helps it grow faster and recover from stress.

• Feeding: 1–2 times per week with small meaty foods (mysis, finely chopped shrimp, reef roids).
• Method: Turn off pumps, gently place food on the tentacles or bubbles, and leave pumps off for 10–15 minutes.
• Parameters: Stable alkalinity (8–9.5 dKH), calcium (400–450 ppm), magnesium (1250–1350 ppm), and low nutrients (nitrate < 20 ppm, phosphate < 0.1 ppm).

Practical Tips for Long-Term Success

• Give at least 3–4 inches of space; bubble coral has sweeper tentacles that can sting neighbors.
• Avoid direct contact with other corals or sharp rock that can cut its tissue.
• When moving it, handle by the hard skeleton, never by the bubbles.
• If tissue recedes, reduce flow, check parameters, and increase gentle feedings.

Watch your bubble coral at night—extended feeder tentacles are a sign it’s ready to eat and generally happy with your tank conditions.