Saltwater Aquarium: Coral Reefs and Halimeda Plants

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Why is halimeda important for coral reefs? For many aquarists, the answer is obvious. Aesthetics is one simple answer to the question, why is halimeda important for coral reefs?

Taking a symbiotic relationship

It would be a no-brainer for an expert aquarist to be asked of the halimeda plant’s importance on the coral reefs. This green plant is a calcareous macroalgae that thrives in tropical oceans and is a perfect example of symbiosis in an aquatic habitat. The halimeda plant is unique in its ability to produce calcium carbonate by synthesizing seawater. This is a characteristic that is also present in purple coralline algae and stony corals.

It is also this trait that gave the halimeda its calcareous classification among aquatic plants. This characteristic appears to be the plant’s adaptation against potential fish grazers. The calcium carbonate that the halimeda produces repels the grazing fish as well as those that are a threat to corals, like the parrot fish and herbivores that also prefer succulent macroalgae. Hence, where the halimeda thrives corals also abound.

An Asset for Reef and Saltwater Aquariums

This plant is a popular choice among those hobbyists knowledgeable at setting up reef aquariums or saltwater aquariums. For one thing, the adaption of the halimeda in an aquarium will contribute to the re-creation of a real marine environment complete with corals, aquatic plants, and tropical fishes. This aesthetic quality is much sought-after by serious aquarists who take pride in the mini-coral reef environment that they create.

The halimeda’s appearance by itself can contribute significantly in the aesthetics of an aquarium. This plant has green, coin-shaped leaves attached together like a chain link. With this appearance, the halimeda is also known as a “money plant” among aquarists. Its shape and coloration can provide interesting contrast with the corals inside an aquarium, while the tropical fishes inside are unlikely to disturb the halimeda because of its calcareous quality.

Important Nutrient Contributor

At the same time, the halimeda will not adversely affect the invertebrates like jellyfishes that may be incorporated into a reef aquarium. On the contrary, the plant can be a factor in the build-up of food nutrients that are beneficial to the fish and invertebrate inhabitants.

Besides its decorative value, there are some other advantages of having the halimeda inside a reef or saltwater aquarium. Like the other marine algae, such as those belonging to the genus Caulerpa, widely used in such tanks, the halimeda provides nutrients useful within the aquarium and its inhabitants. In addition, this plant can serve as a barometer for the alkalinity level of the aquarium water as well as its calcium level.

Alkalinity Barometer

These parameters are particularly important for aquarists who are incorporating corals into a reef or saltwater aquariums. A healthy growth of the plant inside is a good indicator that the prevailing conditions are also good for the corals within the aquarium.

This can very well explain the importance of halimeda plants on coral reefs.

Some regular and careful pruning of the halimeda, however, needs to be done in order for this plant to make its optimum contribution to the aquarium. The halimeda can multiply fast within a tank. It is ideal for them that the water pH level is between 8.1 and 8.4 and the temperature range from 72 to 78 °F.