Seachem Prime Marine & Freshwater Conditioner is a complete, concentrated conditioner for both marine and freshwater aquariums. It effectively removes chlorine and chloramine, and detoxifies ammonia, converting it into a safe, non-toxic form that is readily removed by the tank’s biofilter. Prime detoxifies nitrite and nitrate, allowing the biofilter to more efficiently remove them. It will also detoxify heavy metals found in tap water. It is non-acidic and will not impact pH. Use at startup and whenever adding or replacing water.