Figure shows that 𝐽 !,#$% reduces over time at a decreasing rate. This observation can be attributed to membrane compaction effects caused by the high-pressure water feed acting on the membrane surface during preconditioning, which incurs a reduction in membrane porosity over time. After ~90 minutes of preconditioning the gradient of 𝐽 !,#$% against time approaches zero, which suggests that beyond 90 minutes the transmembrane flux is close to its steady state value. All three runs were terminated after 115 minutes of preconditioning due to time constraints, at which point 𝐽 !,#$% was deemed to have stabilised, meaning that the preconditioned BW30 membrane was ready for experimental use.