Dark substrate for freshwater and saltwater aquariums. Key Features: • Perfect hold for plant roots: substrate with 0.2-0.6mm grain size for freshwater and marine aquariums and terrariums. • Vigorous plant growth: prevents the seeping in of sludge and other waste material with its fine granulation and density. • Ideal for fish, invertebrates and plants: no release of unwanted pollutants into the water. Fine granite sand is gentle on the sensitive barbels of the bottom-dwellers. • No light reflections - full colouring of plants and fish: easily scared animals feel more comfortable and show their full, natural colouring.