RR2-CS Rid O' Rust Extreme Stain Preventer 2x Problem Well Water Stain Preventer Concentrate for Low pH Conditions REPLACES FORMULA 1000 & 3000 Prevents rust and lime scale staining caused by well-based irrigation Case of 4- 64 oz bottles 1- 64 oz bottle is equal to 1 gallon of Formula 1000 1- 64 oz bottle is equal to 1 gallon of Formula 3000