Jar test to determine the need of “Alum” (Aluminiumsulphate)

The aim of adding “Alum” to raw water is to make the water less turbid (turbidity is the term used for explaining how clear the water is and the unit used is NTU). Final turbidity in the water should be less than 5. The process is called flocculation and when the water has been treated with “Alum” it is called pretreated water