Highly concentrated probiotic bacteria. Supplement contains several specially selected bacteria strains. Key function is to transform phosphate, nitrate and organic compounds to a biomass which can be easily removed by skimmer or consumed by corals, sponges, clams and many filter feeders. Bacteria will significantly reduce organic sediment accumulating in the substrate & aquascaping elements. To achieve better results its recommended to place in the sump an additional bacteria medium like Siporax or sand. Bacteria can also be a food source for corals. Pro Bio S protects your tank against pathogenic organisms. Recommended to use in conjunction with -NP Pro or Pro Bio F. Dosage: 1 drop per 100 litres daily (27 US gal).