brand new and high qualityFeatures:This product can effectively remove fish waste, removal of nitrates, phosphates, red moss, etc., to improve water pollution. .This product is particularly suitable for use to open a new tank.It help the tank quickly produce beneficial bacteria.New tank every 100L water use 2 piece. NOT use too much, and suggest after it putted, turn on the air pumpAnd every 7-10 days, use 1 piece per 100L water.Specifications:Material: DrugBottle size: app.4x8.5cm/1.57''x3.35''Color: As the picture shown