We have this CryoPlus 2 LN2 storage unit from ThermoFisher.
To fill it, we regularly have to order “NI 230LT22”, or a 230 L tank of LN2 at 22 psi, from AirGas.
So how often do we have to order a LN2 tank to fill the CryoPlus? Well, here’s a graph for that.

So roughly every 12 to 13 days. Although once in a while, we get a lemon of a tank that empties in roughly a week.