Acropora nana

Acropora nana is a corymbose, thin-branched SPS that sits in the same general look as valida and cerealis types, forming a tight, cushion-like colony of upright branches rather than a sprawling staghorn. In aquaculture it is best known in tri-colour form, with purple and green tones showing through the colony and brighter colour concentrated toward the growing tips. It is a moderate grower when settled, and a healthy colony looks dense and even rather than sparse or leggy.

Care

This is an advanced Acropora for a mature, stable SPS system, not a newly cycled tank. Alkalinity stability matters above all else — hold it steady day to day and avoid chasing numbers with large corrections. Keep calcium and magnesium consistent alongside it, with regular testing to catch drift early. Provide strong, random flow that moves polyps and clears debris without a constant jet aimed straight at the branches. As a high-light species it colours and grows best around PAR 250–400, introduced gradually. Watch for an encrusting base spreading onto the rock and steady polyp extension as the clearest signs the colony is settled and healthy.

Placement and growth

Place Acropora nana high in the aquascape, in the top zone with direct light and strong water movement across the whole colony. Give it at least 2 in of minimum clearance from neighbours so its thin branches are not shaded or stung as it fills in, and so flow is not blocked on one side. Once encrusted, expect moderate, compact corymbose growth; frags that sit without basing down usually need more stability, light, or flow rather than more food.