Enhances Vitality Of Koi And Goldfish,Will Not Adversely Impact On Pond Plants And Useful To Temporarily Reduce Nitrite Toxicity. Direction For Use: When Setting Up A Pond And When Making Water Changes: 100 G (5 Tablespoons) For Each 200 L (50 Us Gallons). This Amount Will Yield 0.5 Ppt. Once Every 6 Months: 250 G (12.5 Tablespoons) For Each 200 L (50 Us Gallons). For Emergency Relief Of Nitrite Toxicity: 1 Kg (3 Us Cups) For Each 200 L (50 Us Gallons). Once Nitrite Toxicity Has Subsided A Water Change Should Be Initiated To Reduce Salinity. (Please Note: Nitrite Levels Do Not Fall, Only The Toxicity To The Fish). The Presence Of High Levels Of Nitrite Indicates A Problem With The Biofilter