Porites

Porites are one of the most important reef-building corals on the Great Barrier Reef and worldwide, forming massive colonies that can live for centuries. In the reef aquarium hobby, they are best known as the host coral for the spectacular Christmas Tree Worms (Spirobranchus). Maintain calcium at 400–440 ppm, alkalinity at 7.5–9 dKH, and temperature between 25–27°C. Porites are hardy and tolerant of a range of conditions, though they grow very slowly compared to most other SPS.

Place Porites in the mid sections of your tank with moderate light (PAR 100–250) and moderate flow. If keeping a Christmas Tree Worm rock, avoid placing it in extremely high flow that could cause the worms to retract constantly. The coral itself benefits from gentle, indirect current that brings food particles to the polyps and worms alike. Porites come in massive, branching, and encrusting forms, with colours ranging from greens and yellows to browns and purples. Branching Porites species are occasionally available from Australian coral vendors and are worth seeking out.

The main challenge with Porites is their extremely slow growth rate — patience is essential. They are not practical fragging candidates due to this slow growth, and the Christmas Tree Worm specimens should not be cut as this would likely kill the worms. If you acquire a Porites rock with Christmas Tree Worms, target-feed the worms with phytoplankton and fine particulate foods to keep them healthy and colourful. For Australian reefers, Porites represent a direct connection to the GBR — keeping them successfully is deeply rewarding.