Flora & Fauna

Fast-growing macroalgae with flat, oval blades on creeping runners. Excellent nutrient export and refugium algae. Can go 'sexual' under stress — turning milky white and releasing gametes, causing a tank crash. Keep under 24h light or harvest regularly to prevent this. Widely available and very effective.

The most popular refugium algae in the reef hobby — tumbling masses of stiff, wire-like bright green strands. Grows rapidly, exporting nitrates and phosphates as it's harvested. Provides a habitat for copepods and amphipods that migrate into the display tank as live food. Extremely hardy.

Feathery, fern-like fronds on creeping runners — arguably the most attractive Caulerpa species. Works well in display refugia where its ornamental appearance is on show. Fast-growing nutrient exporter. Same caveats as other Caulerpa: harvest regularly to prevent sexual reproduction.

Creeping runners bearing upright branches tipped with small spherical beads — resembling tiny bunches of grapes. One of the most vigorous nutrient-exporting macroalgae; grows rapidly in refugia. Can go sexual and crash if left unharvested for too long. Listed as invasive in the Mediterranean.

Attractive calcified green macroalgae with segmented, coin-like lobes. Grows upright and anchors into sandbed or live rock. Naturally calcified — contributes to calcium demand. Fish tend to leave it alone. Adds a natural look to the display tank and provides nutrient export.

Wiry, reddish-brown branching macroalgae that tangs and rabbitfish readily consume. Grows quickly and provides excellent nutrient export in refugia. Attaches loosely to rubble and rock. One of the most palatable macroalgae for herbivorous reef fish — can be offered directly as live food.

Feathery, pinkish-white tufts of jointed calcified branches — a beautiful encrusting coralline relative that forms soft mats on rockwork. Provides habitat for tiny amphipods and copepods. A common and welcome hitchhiker on Mediterranean and Atlantic live rock. Tolerates cooler water than most corallines.

Bushy red-to-burgundy macroalgae prized as live food for herbivorous fish — tangs, rabbitfish, and urchins graze on it enthusiastically. Also an excellent nutrient exporter in refugia. Tumbles well under flow and tolerates a wide range of conditions.

Bright green, tissue-thin sheets of macroalgae familiar on coastlines worldwide. Fast-growing nutrient exporter and a relished food for tangs, urchins, and rabbitfish. Tolerates a very wide temperature and salinity range. Can become weedy if not harvested — keep export-focused.