Yellow Hydnophora

Yellow Hydnophora is a striking coral with a temperament that sits halfway between SPS and LPS, and a personality best described as “looks polite, hits hard.” Its neon yellow-green glow makes it an easy seller, but it needs thoughtful placement to avoid warfare.

Here’s a practical care guide built for real reef farm conditions.

Lighting

Moderate to high light works best. Around 150 to 250 PAR keeps the yellow vibrant and prevents browning. It doesn’t demand extreme light and actually holds color well under mid-range intensities, which makes it flexible for mixed reefs.

Flow

Moderate to strong, with a turbulent pattern. You want water that rolls over the coral from multiple directions so debris doesn’t settle between the ridges. Consistent movement also helps maintain tight polyp extension.

Placement

Give it space. Hydnophora is notorious for tissue-contact aggression. It doesn’t send long sweeper tentacles, but if it touches another coral, it usually wins and melts the neighbor’s tissue. A few inches of buffer is wise.

Place it mid to high in the rockwork where it gets light and flow without brushing against anything.

Water parameters

It thrives under SPS-like stability, though it’s more forgiving than Acropora.

Calcium around 420.
Alkalinity around 8 to 8.6.
Magnesium near 1350.
Nitrate 5 to 15.
Phosphate 0.03 to 0.1.

Ultra-low nutrients can dull the yellow and slow growth. Slightly nutrient-positive systems keep it glowing.

Feeding

Primarily photosynthetic. It does not need direct feeding. Occasional amino acids can sharpen color but not required.

Growth behavior

Yellow Hydnophora forms thick, knobby branches or mounding plates depending on flow and light. Growth is moderate, not explosive, but steady. It develops a sculpted bumpy texture that customers tend to love.

Temperament

Highly aggressive on contact. Think of it as an LPS-style fighter disguised in SPS clothing. Never let it touch fleshy corals or delicate SPS.

Sensitivities

Stable alkalinity matters. Sudden swings can cause recession at the base. It’s not commonly targeted by SPS pests, but it can suffer from bacterial infections if damaged.

Compatibility

Best in SPS-dominant systems or high-flow mixed reefs. With proper spacing, it becomes a safe and stunning centerpiece.