Porites rus

Porites rus is a stony coral that forms broad plates, irregular columns and short, fused branches within the same colony. Its polyps are very small and make the surface look like fine velvet. It has cream, yellow, purple, blue and green forms. In older literature it appears in the genus Synaraea. It is considered one of the hardiest stony corals and grows fast under the right conditions, which makes it suitable for getting started with SPS. Trade in stony corals is subject to CITES Appendix II; choose an aquacultured frag.

• Light: Moderate light; roughly 150–300 PAR. It also lives under lower light, but its color darkens.
• Flow: Moderate, random flow; no detritus should build up on the surface.
• Placement: The middle part of the rockwork, on a surface where the plates can open out sideways. Because it spreads quickly, keeping it on a separate rock makes it easier to control.
• Water parameters: Salinity 1.025–1.026, KH 7–9 dKH, calcium 400–450 mg/L, magnesium 1250–1400 mg/L. Its tolerance of nutrients is high; it does well at nitrate 2–15 mg/L and phosphate 0.03–0.1 mg/L.

It is photosynthetic; light and zooxanthellae algae provide most of its energy. No extra feeding is needed; the fine particles in a regularly fed aquarium with fish are enough.

It is a peaceful coral, but its rapidly expanding plates shade neighboring corals and grow toward them. Leave 10 cm of space and trim its edges if necessary. Long-tentacled LPS sting it. Put new pieces through a coral dip to guard against Porites-eating nudibranchs (Phestilla).