A home medical device system 110 includes a home therapy machine 100 (for example a dialysis, drug delivery or nutritional therapy machine) for performing a home therapy on a patient a user interface 122 operably connected to the home therapy machine which receives operator inputs a water treatment device 10 in fluid communication with the home therapy machine and a data connection between the home therapy machine and the water treatment device. In a first embodiment wherein the home therapy machine transmits data via the connection to the water treatment device for control of the water treatment device, the data provided based on at least one of the operator inputs received via the user interface. In a second embodiment the home therapy machine transmits data via the connection to the water treatment device, where the data is based on a therapy prescription sent from a server 118 to the home therapy machine. In a third embodiment the water treatment device is configured to transmit data via the connection to the home therapy device which then forwards the data to a server 118.
