Several types of minerals can be found in tap water. Minerals containing calcium and magnesium are common in local groundwater supplies and are responsible for the white spots observed when tap water is allowed to dry on household surfaces. While these spots may be unwelcome, these naturally occurring minerals in your tap water provide a protective internal coating deemed optimum for controlling corrosion of your home’s water pipes and plumbing fixtures. The most common mineral deposits are lime, rust, and calcium.
Mineral deposits that are allowed to accumulate over time on household surfaces can become more problematic to remove. Routine household maintenance such as wiping water droplets from surfaces before evaporation occurs can help prevent mineral deposits.