RR2-2.5 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 2- 2.5 gallon bottles 1- 2.5 gallon bottle is equal to 1- 5 gallon bucket of Formula 1000 1- 2.5 gallon bottle is equal to 1- 5 gallon bucket of Formula 3000