Aqualibrium First Aid Salt Additive 780gAqualibrium First Aid Salt is a unique physiological salt formula which helps freshwater fish maintain a constant internal salt/fluid balance. This is particularly useful when fish are stressed or sick because the salt/fluid balance inside the fish can be negatively effected threatening the fish\'s welfare.Aqualibrium First Aid Salt Additive is one of the fish keeper\'s most versatile treatments. It can be used in a variety of ways: As a general aquarium tonic As a mild pH buffer (also reducing the toxicity of Nitrite) To help minimise the effects of stress on aquarium fish As a supportive measure when treating for disease