Prime is the complete and concentrated conditioner for both fresh and saltwater. Prime removes chlorine chloramine and detoxifies ammonia. Prime converts ammonia into a safe non-toxic form that is readily removed by the tank biofilter. Prime may be used during tank cycling to alleviate ammonia/nitrite toxicity. Prime detoxifies nitrite and nitrate allowing the biofilter to more efficiently remove them. It will also detoxify any heavy metals found in the tap water at typical concentration levels. Prime is non-acidic and will not impact ph. Prime will not over activate skimmers. Use at start-up and whenever adding or replacing water.