The invention relates to an arrangement for a device for disinfecting a fluid, having a container； a reactor space which is arranged in the container and is configured to receive a fluid to be disinfected, which enters the reactor space via an inlet thereof and can leave it via an outlet of the reactor space； and a UV irradiation device having light-emitting UV diodes, with which UV light rays for disinfecting the fluid in the reactor space can be irradiated； wherein the reactor space in the container is formed having a flow path in a flow tube surrounded by a container wall and the light-emitting UV diodes are arranged distributed on the container wall in the region of the flow tube along the flow path in order to irradiate the UV light rays on the flow path. Furthermore, a device for disinfecting a fluid is provided.
