The answer to 'downspouts water stains' is that downspouts can often develop water stains and discoloration due to mineral deposits, algae growth, or rust. This is a common issue that homeowners face, but it's usually not a serious problem and can often be addressed with some basic cleaning and maintenance.
The most common causes of downspout water stains are mineral deposits from hard water, algae growth from moisture and organic matter, and rust from older metal downspouts. These stains can range from light discoloration to thick, unsightly buildup. While they may be unsightly, they generally don't indicate a more serious issue with the downspout or gutter system.