JBL Sansibar DARK Dark substrate for freshwater and saltwater aquariums. - 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 release of unwanted pollutants into the water. Fine, round-shaped granite sand is gentle on sensitive barbels of bottom-dwellers. - No light reflections – full colouring of plants and fish: easily scared animals feel more comfortable and show their full, natural colouring - Contents: 1 bag Sansibar Dark. Not really suitable for undergravel heating cables Product information Ideal substrate The substrate is an important part of the aquarium components because a lot of animals dig in the ground to search for food. The plants also need a safe hold and have to absorb the food in the ground through their roots. Digging fish absolutely need a substrate which is not sharp-edged. Undergravel heating can only be recommended for medium-fine to coarse substrates because water circulation cannot really build up in very fine substrates. Use: Rinse the substrate with tap water to remove any abrasion caused in transit. Put substrate on the nutrient substrate (JBL AquaBasis) to promote the plant growth (for vigorous growth about 6-8 cm). Calculation formula The right amount of substrate: length (cm) x width (cm) : 140 = kg substrate with 5 cm thickness.