Hardness of water is due to the presence of calcium and magnesium salts.
Water is the most essential compound needed for life on Earth to survive. Oceans, rivers, wetlands, lakes, glaciers, and other bodies of water all contain water. Rainwater is considered pure because it has no salt dissolved in it, despite the presence of dissolved gases.
Classification of water
Water can be classified as hard water and soft water.
- Soft water
Soft water is characterized as surface water with low ion concentrations, especially calcium and magnesium ions. Where rough, impermeable, and calcium-poor rocks are responsible for the creation of run off and river drainage basins, soft water naturally occurs.
- Hard water
Hard water is a phrase that indicates water having a very high mineral content. As water percolates into deposits of calcareous, gypsum or chalk that are primarily comprised of carbonates of magnesium or calcium, bicarbonates and sulfates, hard water is formed.