A patient connector for dialysis is disclosed. In an example, a patient connector includes a housing including an inlet and an outlet and defining at least one aperture. The patient connector also includes a seal initially blocking the outlet and a hydrophobic filter covering the at least one aperture of the housing. The patient connector further includes a check valve positioned and arranged to prevent air from being vented from the housing via the at least one aperture and through the hydrophobic filter when the housing is under atmospheric pressure or negative pressure. The check valve is configured to allow air to be vented from the housing via the at least one aperture and through the hydrophobic filter when the housing is under positive pressure.