API Tap Water Conditioner treatment removes toxins from tap water instantly, so you can add fish to your aquarium or add them back after a water change immediately. API Tap Water Conditioner treatment dechlorinates aquarium and tap water, detoxifies heavy metals, and may be used in both fresh and saltwater. As a rule, all tap water must be treated before adding fish to make sure they remain healthy. Tap Water Conditioner is super concentrated with one 30 ml / 1 oz bottle, treating up to 2250 Ltrs / 600 US Gallons of aquarium water.