What primarily causes red water problems?

Red water problems are primarily caused by iron. Iron is commonly found in many water distribution systems and can originate from corroding pipes, especially those made of iron or steel. Over time, as these materials corrode, iron particles can be released into the water supply, giving it a reddish or brownish tint. This can lead to aesthetic issues, such as staining laundry and fixtures, and may raise concerns about water quality, even if the water is safe to drink.

Chlorine residual is important for disinfection but does not typically cause red water. Algae, while it can contribute to water quality issues, tends to cause greenish discoloration due to chlorophyll rather than reddish hues. Copper may lead to blue or green staining from corrosion but does not contribute to the red discoloration observed in water. Thus, iron is the primary culprit responsible for red water problems in distribution systems.