This beautiful natural basalt gravel is perfect for aquarium substrates! Natural and safe: The aquarium gravel is 100% natural and safe. It does not contain any artificial additives or coatings, so it behaves in a water-neutral way and does not release any polluting substances.Decorative use: The black basalt gravel creates impressive contrasts in the aquarium due to its dark shade, helping present an attractive underwater landscape.Benefits: With rich trace elements, the basalt stone ensures good rooting and rapid growth as well as the attractive appearance of plants. Besides, it is ideal for aquariums inhabited by timid fish that prefer dark substrates.Wide applications: The black basalt looks beautiful both wet and dry, making it ideal for gardens, pathways and other landscapes.