River water containing two types of spherical suspended particles $\text{(clay particles, metal particles)}$ is retained in a sedimentation tank. The clay particles having diameter of $75 \mu \mathrm{m}$ and specific gravity of $2.65$ is settling in the tank with a constant velocity. The velocity of clay particles is $2$ times of that of metal particles having specific gravity of $8$. Assume discrete settling and laminar flow conditions within the sedimentation tank. The estimated diameter of the metal particles is ___________ (in $\mu \mathrm{m}$, $\text{rounded off to integer)}$
