Does water with very low hardness tend to be less aggressive?

Water with very low hardness is typically more aggressive. Aggressiveness in water refers to its ability to dissolve minerals from pipes and fixtures, particularly metals like lead and copper. Water hardness is primarily a measure of the concentration of calcium and magnesium ions. When hardness is low, it often indicates a lower presence of these ions, which can stabilize the water and reduce its tendency to corrode.

Conversely, low hardness often correlates with higher acidity or lower pH levels, conditions that can enhance the water's aggressive nature. Soft waters can leach metals from plumbing and fixtures more readily compared to harder waters, which tend to deposit minerals that help form protective scales on the pipes’ surfaces, thus stabilizing them.

Understanding this characteristic is essential for water treatment professionals as it affects the materials and methods used in water distribution systems and treatment processes. Addressing water aggressiveness is crucial to avoid corrosion-related issues and ensure the longevity of infrastructure.