Fire starter Hirsuta

Lighting

Moderate to high light, around 180 to 250 PAR. Higher light strengthens the orange or red “fire” coloration on the growth tips, while lower light softens the base into duller greens or browns. Montipora hirsuta adapts well but prefers stable intensity.

Flow

Moderate to strong, with a turbulent pattern. Hirsuta forms fuzzy, elongated ridges and branches that trap debris without good flow. Intersecting currents keep the polyps extended and the surfaces clean.

Placement

Mid to high rockwork. It grows as a mix of encrusting plates and upright fingers, so give it horizontal and vertical room. Hirsuta doesn’t cast heavy shade compared to digitatas, but it can still overgrow slower neighbors.

Water parameters

More forgiving than acros, but still wants SPS consistency.

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

Letting nutrients crash will drain color from both the base and the tips.

Feeding

Relies mainly on light and dissolved nutrients. Occasional amino acids can deepen the reds and oranges. No target feeding needed.

Growth behavior

Moderate growth. It encrusts quickly, sending up fuzzy, irregular upright ridges and short branches. Polyps stay extended most of the day, giving it a soft, shaggy look. Fragging is very easy, as branches snap cleanly.

Sensitivities

Montipora-eating nudibranchs are the main pest risk. Look for pale patches or tissue loss at night. Alk swings can cause tip burn but hirsuta usually recovers as long as parameters stabilize.

Compatibility

Peaceful coral with no long sweepers. It competes by steady encrusting growth rather than aggression. Keep it away from very slow LPS so it doesn’t overrun them.