Saltwater plants, which are commonly used in aquariums, are both beautiful and useful, as their long weed-like tentacles protect tiny fish from predators. A standard potted plant will shrivel and die in saltwater because the salt extracts water from a plant’s cell. Saltwater plants are protected from the salt by a special layer of tissue.
The halimeda is a green saltwater plant that originated around the Caribbean Sea. It's a popular aquarium plant offering decorative qualities, and is known as the money plant because it has coin-shaped green leaves that are linked to one another in winding rows. This plant thrives best in an environment with a high concentration of calcium. A water pH that ranges from 8.1 to 8.4 is ideal, according to the Saltwater Aquarium Guide website. If the Halimeda fails to get enough calcium through calcium supplements, its color can fade to white. Iron is also helpful, but not critical.
Red Grape Algae
Red grape algae are able to grow quickly under intense water flow and higher lighting conditions than most other green algae. This plant doesn’t tolerate inferior water conditions, and needs to be in water that’s lower in nutrients. It shouldn’t be placed in a tank containing tangs and other herbivores.
Maiden hair, also known as turtle grass, is a green saltwater plant so-named because it resembles thin tufts of hair. Tangs and other fish don’t like the taste of this plant, so they leave it alone. It needs good lighting and a moderate to strong water current. Maiden hair can’t tolerate high levels of nitrates or copper. They are usually sold attached to a small piece of rock.
Mermaid Fan Plant
The mermaid fan plant is a decorative saltwater plant that grows in the form of beautiful fan-shaped leaves. This hardy plant thrives in aquariums that have lower levels of nutrients such as phosphates and nitrates. It is also used in refugiums, which are compartments isolated from the rest of an aquarium population. Most invertebrates and herbivorous fish will not eat this plant.
Spaghetti algae, also called green hair algae, are ideal for controlling phosphate and nitrate in a refugium. The plant’s long green, threadlike clumps look like an old fishing line ball. It grows rapidly and is usually not consumed by herbivorous species. It receives its nutrients best when housed in a refugium, where water is able to move in a tumbling motion around it. Good lighting is important for this plant. Iron can be substituted for nutrient-rich water, but too much can cause hair algae to grow, which can be a nuisance.