<p>Hello, I am using a 2D unsaturated model with the pFreeze plug-in. I use a time series of fluid flow as upper boundary condition. While runnung, the model hydraulic head values reach unreasonably high and low head values (~ 1e-9 m). It is probably a bug that is related to the pFreeze plug-in. As a way around it, is there a way to constrain min/max head values in all the model nodes?&amp;lt;/strong&amp;gt; I tried aplying a min/max boundary condition to all nodes, and also an 'if, else, end' condition in the 'Current expression'. Nothing works. Does anyone have an idea how to limit the min/max range of hyd' head in all nodes? Thanks in adnance, Matan.</p>