Blackwood is a natural wood often used in aquariums and terrariums for its dark, aesthetic appearance. Of tropical origin, it is dense and durable, providing an ideal natural setting for aquariums, paludariums, and terrariums. It can release tannins, which slightly acidify the water and create a "black water" effect beneficial to some species. Pre-soaking is recommended to prevent it from floating and to limit the release of tannins.