JBL Sansibar Red is a red, fine gravel for any aquarium, aqua-terrarium, nano aquarium etc.. JBL Sansibar Red is a fine rounded quartz sand, just like the one found in the native waters of the aquarium fish. It is gentle on the sensitive barbels of bottom-feeding fish such as cory catfish and loaches. The fine grain size and dense layering prevent sludge and other debris from seeping in, thereby preventing decay processes which could hamper plant growth. Ideal in combination with JBL AquaBasis plus for perfect plant growth. Not suited for undergravel heating cables. JBL Sansibar Red does not release hardness-producing substances or undesired silicates into the aquarium water. Grain size: 0.2 - 0.6 mm.