Method for sanitizing mobile potable water preparation and storage systems for providing potable water of a high sanitary quality, characterized in that a. a reagent set is provided which consists of three separate components in stoichiometrically matched amounts, wherein the first component is an acidic solid component or acidic liquid component in the form of an aqueous cleaning concentrate with a pH <3, which contains mineral acids in the form of the mineral acids: phosphoric acid, sulfuric acid and/or nitric acid, and/or the acidic salts thereof, the second component contains a strong halogen-free oxidizing agent in the form of alkali metal percarbonates, alkali metal peroxides and alkali metal perborates or of hydrogen peroxide in an aqueous solution, wherein the amounts of the first and second components are selected in such a way that when mixed and diluted with respect to an amount of 100 l of an aqueous sanitizing solution, a sanitizing solution having a pH of less than 3 and an active oxygen content corresponding to a hydrogen peroxide content of 650 to 900 ppm in 100 l of aqueous sanitizing solution, is obtained, and the third component contains in combination substances which react alkaline in aqueous solution and reducing agents for the complete reduction of the strong halogen-free oxidizing agent of the second component in the used sanitizing solution in solid or liquid form, wherein the third component contains alkali metal hydroxides, alkali metal carbonates and/or basic alkali metal phosphates as substances which react alkaline in aqueous solution, and alkali metal salts and alkaline earth metal salts of the dithionous acid, of the sulfurous acid, of the disulfurous acid and of the thiosulfuric acid as reducing agents, b. the first and second components are mixed together to form an aqueous sanitizing solution and are optionally mixed with an additional predetermined amount of water, c. the resulting aqueous sanitizing solution is allowed to act on the surfaces in contact with potable water and on the technical equipment and pipes of a mobile potable water system, d. the sanitizing solution is removed from the mobile potable water system after a predetermined exposure time and the system is rinsed with water thereby substantially completely removing the components of the sanitizing solution; and e. the exhausted sanitizing solution and collected rinsing water from step d. are combined and neutralized by adding the third component and then disposed of. a. a reagent set is provided which consists of three separate components in stoichiometrically matched amounts, wherein the first component is an acidic solid component or acidic liquid component in the form of an aqueous cleaning concentrate with a pH <3, which contains mineral acids in the form of the mineral acids: phosphoric acid, sulfuric acid and/or nitric acid, and/or the acidic salts thereof, the second component contains a strong halogen-free oxidizing agent in the form of alkali metal percarbonates, alkali metal peroxides and alkali metal perborates or of hydrogen peroxide in an aqueous solution, wherein the amounts of the first and second components are selected in such a way that when mixed and diluted with respect to an amount of 100 l of an aqueous sanitizing solution, a sanitizing solution having a pH of less than 3 and an active oxygen content corresponding to a hydrogen peroxide content of 650 to 900 ppm in 100 l of aqueous sanitizing solution, is obtained, and the third component contains in combination substances which react alkaline in aqueous solution and reducing agents for the complete reduction of the strong halogen-free oxidizing agent of the second component in the used sanitizing solution in solid or liquid form, wherein the third component contains alkali metal hydroxides, alkali metal carbonates and/or basic alkali metal phosphates as substances which react alkaline in aqueous solution, and alkali metal salts and alkaline earth metal salts of the dithionous acid, of the sulfurous acid, of the disulfurous acid and of the thiosulfuric acid as reducing agents, b. the first and second components are mixed together to form an aqueous sanitizing solution and are optionally mixed with an additional predetermined amount of water, c. the resulting aqueous sanitizing solution is allowed to act on the surfaces in contact with potable water and on the technical equipment and pipes of a mobile potable water system, d. the sanitizing solution is removed from the mobile potable water system after a predetermined exposure time and the system is rinsed with water thereby substantially completely removing the components of the sanitizing solution; and e. the exhausted sanitizing solution and collected rinsing water from step d. are combined and neutralized by adding the third component and then disposed of.