A dialysis system includes a dialysis machine with a variable fluid demand including at least a lower demand and a higher demand. A fluid source is in fluid communication with the dialysis machine and provides fluid to the dialysis machine at a fluid flow rate. A flow regulation device includes a fluid inlet in fluid communication with the fluid source and a fluid outlet in fluid communication with the dialysis machine. The flow regulation device is operable to expand and contract to provide a variable internal volume. The flow regulation device expands when the dialysis machine has the lower demand and contracts when the dialysis machine has the higher demand.