Seachem Prime is the most complete and concentrated water conditioner for both freshwater and saltwater aquariums. Prime removes chlorine, chloramines, and ammonia. Ammonia is converted into a safe, non-toxic form that is readily removed by the tank’s bio-filter. This product is best used during tank cycling to alleviate ammonia/nitrite toxicity. Prime detoxifies nitrite and nitrate, allowing the bio-filter to more efficiently remove them, making a safer and healthier environment for your fish. It also promotes the production and regeneration of the natural slime coat of your pet fish. This product is non-acidic and will not impact pH. Use at start-up and whenever adding or replacing water. Instructions: Use 2 drops for each 1 gallon of new water. Product may be added to the aquarium directly, but it is better if added to new water first. Size: 250 ml (Treats up to 2,500 gallons of water)