Rust and Mineral Stains: Causes and Solutions

What causes the reddish-brown staining on the sides of your home, community buildings, sidewalks, driveways, and pavement? Where are the spots on your vehicle originating?

Iron Staining – Sidewalks and Structures

iron stains on driveway

Rust stains from iron on concrete driveway

Those reddish-brown stains on surfaces and structures are iron stains. Iron stains are caused when irrigation water has high dissolved iron content. When irrigation systems draw lake water, they also draw in the dissolved iron existing in the water. As irrigation system sprinklers water the grounds, the dissolved iron oxidizes and leaves behind rust stains wherever it lands.

Iron in Lake Water

Iron can be present in lake water in many forms; the soluble ferrous iron and the insoluble ferric iron are the most common. Water containing ferrous iron is clear and colorless, but when exposed to air, the water turns cloudy causing a reddish-brown spray of ferric iron. Iron in the irrigation water supply above 0.1 ppm may plug up drip irrigation and when iron levels exceed 0.3 ppm, iron staining may occur on hard surfaces, concrete, and structures.

Minerals in Lake Water

mineral stains on car

Mineral stains from irrigation on a car

It is common for lake water in Florida to haveĀ  a high mineral content. These minerals can cause stains on surfaces, glass, and vehicles. Irrigation systems that draw water from lakes spray whatever is in its path, leaving behind circular white or gray mineral stains after the water droplet evaporates. These calcium and mineral deposits can be difficult to remove. The best solution for mineral staining is to redirect the irrigation spray heads away from vehicles and glass surfaces.

What is Not Causing Iron and Mineral Stains

Aquatic Systems does not add anything to the water of lakes, ponds, mitigation areas or other natural water bodies that would cause iron or mineral staining on surfaces or structures. Iron staining originates from ferrous well water or natural iron in lake water that is drawn for irrigation purposes.

To prevent iron staining from lake-sourced irrigation systems, Aquatic Systems can perform water testing to determine iron and oxygen levels in your lake and provide your community with affordable, practical solutions for rust stains.


Call 800-432-4302 or Contact Us Today!