There several species of reefs, such as small polyps, that do quite well in aquariums with other organisms, such as tropical fish. Coral reef such as these can absorb organic substances that have dissolved in the water, or bacteria from plankton. Many types of reef even thrive on food from residual waste of the fish in the aquarium and foods that they leave behind. There are often algae that grow on the reefs that provide an indirect food supply, because the algae grow their own food from the light.
Algae, which are part of the Zooxanthallae family, have a symbiotic relationship with the reef and the tropical fish. Coral reef feed better from the algae, however, for smaller or medium-sized corals, and only when there is sufficient light. Tank owners must be careful when they are feeding their coral reefs, though, because they might regurgitate indigestible food, which could increase the nitrate in the aquarium.
This could be toxic to the reef and other organisms, such as the tropical fish. Coral reef owners can solve this problem by making regular water changes in their tank. They should also make arrangements to rinse the coral's water periodically, which requires an aquarium pump and filter system. It is worth it, however, to ensure the long life an health of thee beautiful creatures.
