Final answer:
Hard water in cleaning milking equipment is primarily caused by excess calcium and magnesium, which are removed through water softening processes like ion exchange or lime softening to prevent scale buildup and improve cleaning efficiency.
Step-by-step explanation:
The cause of hard water in cleaning milking equipment is primarily due to an excess of calcium (Ca2+) and magnesium (Mg2+) ions. These minerals can lead to scale formation and decrease the effectiveness of soap, causing cleaning challenges. To rectify this, water softening processes like ion exchange or lime softening are used to replace hard water cations with softer ones such as sodium (Na+), which lessens the water's hardness and prevents scale buildup. Hard water develops naturally from the dissolution of calcium and magnesium carbonates in soil, and while it does not harm health, it can cause various practical issues.