A medical fluid treatment system includes a source of purified water； at least one concentrate for mixing with the water from the source to form a treatment fluid； a disposable set including a pumping portion, a concentrate line in fluid communication with the concentrate source and the pumping portion, and a patient line in fluid communication with the pumping portion, the patient line including a filter having a membrane configured to filter the treatment fluid, the filter configured such that (i) fresh treatment fluid flowing from the pumping portion towards a patient flows through the membrane and (ii) used treatment fluid flowing through the filter from the patient to the pumping portion bypasses the membrane； and a medical fluid delivery machine including a pump actuator operable with the pumping portion of the disposable set.
