A container (14) with a content (8) has at least one hypochlorite compound, in particular a calcium hypochlorite compound, for generating an aqueous solution, and at least one inlet attachment (46) for attachment to a water supply line (48) and at least one outlet attachment (50) for attachment to an outlet line (52, 92) for a liquid composed of the incoming water and of the content (8), wherein the content (8) is located in accordance with the flow between the inlet attachment (46) and the outlet attachment (50), and the container (14) is designed as a transportable exchange unit that is sealed off from the outside in the unattached state.