Classification of Hardness

Classification of hardness can be categorized based on some parameters such as based on metal ions, based on anion that has association with metal ion and based on CaCO3 content.

Classification of hardness based on metal ion can be divided as follow:

1. Calcium hardness
2. Magnesium hardness

Classification of hardness based on anion that has association with metal ion can be divided as follow:

1. Carbonate hardness
2. Non-carbonate hardness

Classification of hardness based on CaCO3 content can be divided as follow:

1. Soft hardness if contains 0-75 mg/l CaCO3 content.
2. Semi hardness if contains 75-150 mg/l CaCO3 content.
3. Hardness if contains 150-300 mg/l CaCO3 content.
4. Very hardness if contains more than 300 mg/l CaCO3 content.