Blagdon Pond Guardian Large Tonic Salt (9.08kg)Essential physiological salts to promote pond fish health. Mild pH buffer Protects fish against disease Easy to use can be added directly to a pond 9. 08kg treats up to 9. 092 litres (2000 Gallons) Pond Guardians unique formulation helps to create the perfect environment for pond fish. This product stabilises pond water conditions, including all the important pH value. Pond Guardian is a major ally in your fishes struggle to maintain a constant