Particle scale height evolution of run SI30-4-2-c and run SI30-4-4-c. Each particle in the simulation has a unique size within the given size range. Particles are grouped into six size bins for illustration purposes. To ensure that the diffusion of the small particles is not limited by the simulation box, we performed the same simulation in a 0.4 × 0.4H_g box in the right panel. The scale heights of the large particles converge while the smallest species saturate to a larger H_p than in the left panel.