Comparison between the full coagulation model DustPy (upper row, 171 dust fluids) and our new three-parameter power-law prescription TriPoD, which we implemented in the PLUTO code (two dust fluids). We show two snapshots of the one-dimensional disk models in the first two panels in each row. The third panel shows the local dust size distribution of the respective model at 10 au for both snapshots. The light grid in the background represents size distribution power laws with n(a) ∝ a^−3.5 and n(a) ∝ a^−3.0.