Leptoseris

Leptoseris are deep-water SPS corals that thrive under lighting conditions that would starve most stony corals. Found naturally at depths of 30–80 metres on reef walls and overhangs, they are uniquely adapted to low-light environments. Maintain calcium at 400–440 ppm, alkalinity at 7.5–9 dKH, and stable temperature between 25–27°C. Their low-light preference makes them perfect for filling shaded areas of your tank where other SPS simply will not survive.

Place Leptoseris on the sand bed or lower rockwork, ideally under overhangs or in shaded spots receiving PAR of 50–150. Too much light will cause them to bleach or brown out — if you notice pale patches, move the coral deeper. Moderate, gentle flow is ideal; Leptoseris are thin, plating corals that can be damaged by strong direct currents. They come in striking colours including orange, green, purple, and the highly sought-after rainbow varieties. Under blue actinic lighting, their fluorescence can be spectacular.

Leptoseris grow slowly compared to other SPS but are quite hardy once established. Fragging requires care due to their thin, brittle skeleton — use a bandsaw or Dremel for clean cuts. In Australia, Leptoseris are becoming increasingly popular as reefers discover how to utilise dim areas of their tanks. They are naturally found throughout the Indo-Pacific including deeper sections of the GBR. Supplemental feeding with fine phytoplankton or amino acids can boost growth and colour in these light-limited corals.