Seachem Prime is a complete conditioner for both marine and freshwater use that removes chlorine, chloramine, and detoxifies ammonia and nitrite. It also provides essential ions and stimulates natural slime coat. It will also detoxify any heavy metals found in the tap water at typical concenration levels. Prime also enhances nitrate removal. It should be the first choice conditioner when setting up a new tank, adding, or changing water. No other product is required to make water safe, even in high chloramine situations. Unlike competing products, Prime does not cause a pH drop or over-activate skimmers. A 100 mL bottle treats over 1,000 gallons, much more than competing products. Marine and freshwater.