Hardness strips are used to test for the removal of which minerals?

Hardness strips are specifically designed to test for the presence of calcium and magnesium in water. These minerals are the primary contributors to water hardness, which affects various aspects of water quality, including its taste, the behavior of detergents, and the buildup of scale in plumbing and appliances.

Calcium and magnesium ions in water interact with certain reagents on the hardness strips, resulting in a color change that indicates their concentration. By using these strips, one can effectively measure the hardness of water, helping to determine if water treatment processes, such as softening, are required to reduce these mineral levels. This is particularly important in various applications, including household water systems, industrial processes, and agricultural practices.

In contrast, the other choices involve minerals that do not contribute to water hardness; therefore, they are not tested by hardness strips. Sodium and potassium, for instance, are typically more related to the salinity of water, while iron and manganese can affect color and staining but do not significantly influence hardness. Lead and copper are contaminants often monitored for safety rather than hardness. Thus, calcium and magnesium stand out as the correct minerals associated with hardness testing.