Halimeda discoidea

Decaisne 1842

Money Plant

Range: Tropical Western Atlantic Ocean: Caribbean.

Natural Environment: Grows upright, compact, often as dense clumps to 8 inches (20 cm) high, and only found on hard surfaces, e.g., shells, pebbles, rocks, or sand covered hard surfaces up to 100 feet (30 m) deep in coastal bays and lagoons.

General Husbandry: Prefers medium to indirect light. Besides needing a calcium level near that of Natural Seawater (NSW), about 400 ppm, it appears to do better if alkalinity is maintained between 3.5 - 4.5 meq/l or even slightly higher.

When this alkalinity range is maintained have seen these species of algae grow in my aquariums at a rate of .25 inch (.6 cm) per day. It's a good species for aquariums with grazers such as Tangs because the calcareous makeup of the plant helps keep their digestive system free of blockages. H. incrassata is another aquarist favorite.

Taxonomy:

Kingdom: Plantae

Phylum: Chlorophyta

Class: Ulvophyceae

Order: Bryopsidales

Family: Halimedaceae

Genus: Halimeda

FYI: Often called Cactus Algae or Money Plant.