JBL Sansibar River is a natural substrate for any aquarium. JBL Sansibar River consists of coarse-grained, rounded sand. Ideal for digging animals such as rays, Kuhli loaches, catfish, etc. Injuries to the mucous membrane are prevented by the coarse-grained, rounded structure. It is gentle on the sensitive barbels of bottom-feeding fish such as cory catfish and loaches. JBL Sansibar River does not release hardness-producing substances or undesired silicates into the aquarium water. Grain size: 0.4 - 1.4 mm.