Perfect hold for plant roots: substrate with 0.2 - 0.6 mm 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 unwanted pollutants released into the water. Fine, round-shaped granite sand is gentle on sensitive barbels of bottom-dwellers. Use: spread substrate on top of the nutrient substrate (approx. 6-8 cm for vigorous plant growth) Contents: 1 bag Sansibar White. Not really suitable for undergravel heating cables