Use Rid O' Rust RR1 to prevent UGLY rust stains caused by irrigation well water. Apply the formula through American Hydro Systems injection or siphoning system to prevent sprinkler stains from well water forever. RR1 is used for water with a pH of 6 or greater and any hardness level. 1/2 Gal. (64 oz.) of RR1 will treat 125,000 Gal. of water with 1 ppm iron. Keep the rust and iron staining off all your outdoor surfaces using Rid O Rust preventers. Rid O Rust has been a trusted brand for rust prevention for over 25-years.