Halimeda

Halimeda sp.

Care Level	Easy
Lighting	Moderate
Water Flow	Low to moderate
Placement	Refugium, sump, or display
Aggression	Beneficial — none
Coloration	Green calcified segments (cactus-like)

Overview

Halimeda (the “Money Plant” or “Cactus Algae”) is a calcified green macroalgae made of chained, coin-like segments. It exports nutrients like other macroalgae, but because it builds a calcium-carbonate skeleton, most fish and pest algae leave it alone — so it can be grown right in the display as decoration.

Care & Placement

Grow in a refugium, sump, or display under moderate light. It anchors into sand or rock. Because it pulls calcium from the water to build its segments, keep an eye on calcium and alkalinity if you grow a lot of it.

Feeding

Photosynthetic; consumes nitrate and phosphate plus calcium. No feeding needed.

Propagation

Spreads on its own by growing new segments; can be divided.

Cautions

Uses up calcium and alkalinity as it grows — top up as needed in tanks with a lot of it. When it dies back it can release stored nutrients, so remove dying (white) sections. Otherwise a hardy, decorative, well-behaved macroalgae.