Abstract: An IV system can include a first flow regulator configured to restrict flow through a tube and a second flow regulator configured to restrict flow through the tube downstream of the first flow regulator. The first flow regulator can compress the tube a fixed amount to set an initial flow rate through the tube, while the second flow regulator includes a user-adjustable mechanical compression device that compresses the tube to a variable degree to fine-tune the flow rate through to a more precise flow rate that is lower than the initial flow rate. The flow regulators can utilize a purely mechanical means such that electricity is not required. Such systems can provide a simple, low-cost, and low-power way to provide precise flow control to patients, especially neonatal patient, in any environment. Systems can also include flow rate monitoring, alerting, and shutoff components.