A device for extracorporeal blood treatment comprising at least a first concentrate connection which is set up to feed at least a first concentrate into the device for extracorporeal blood treatment as the basis for generating a dialysate at least a second concentrate connection which is configured to feed at least a second concentrate into the device for extracorporeal blood treatment as the basis for generating a dialysate wherein the device for extracorporeal blood treatment is configured to switch over from supplying the at least first concentrate to supplying the at least second concentrate at a predetermined time or after a predetermined period of time during an ongoing blood treatment.
