Our most aggressive acid-based product for the removal of rust, scale, hard water and organic deposits from any metal surface. Excellent for internal air conditioner coils, steam cleaners, dishwashers and boilers. Our most aggressive acid-based product for the removal of rust, scale, hard water and organic deposits from any metal surface. Excellent for internal air conditioner coils, steam cleaners, dishwashers and boilers. pH 1.0 Use dilution : 6 - 32 oz/gal.