Seachem's Renew is the ideal filter media for systems where phosphate released from all activated carbons poses a problem. Less aggressive than carbon, Renew is well suited for reefs and planted habitats as well as in soft water habitats. Renew removes organics and particulates in the sub-micron range while also helping control ammonia, nitrates, and phosphates in the water. Features: Removes organics and particulates. Control ammonia, nitrates, and phosphates. Benefits: Gentle and less impactful on water pH and hardness. Less aggressive than carbon, safe for plantlife. Directions: Should be used in exactly the same manner as activated carbon. Use 250mL for each 120-160L (30-40 US gallons). For best results, Renew should be placed so as to maximize the flow of water through it. Use in a filter bag such as Seachem's Zip Bag. Although Renew is clean, it is advisable to rinse before use. It lasts about the same as carbon (4-6 weeks).