This tour we did in December 2017. It is a beautiful but also challenging tour on the Israel National Trail.
We parked the car in Midreshet Ben Guion (end ponit), took the bus to Tsafit Junction on Hwy 25 and hitched to the first night camp at Mezad Tamar (starting point).
We filled up water at the water tank on top of the small crater and at the Oron factory. As the temperatures were moderate, we only needed 2-4 liters per day per person and had 8 liters water capacitiy per person. This is not a recommendation! Everyone has to decide, how much water to carry!