Free and porous media flow 3D simulation - convergence issues

hey all,

I was using the free and porous media flow module (fp) to understand flow distribution patterns in my system. in the 2-D form it was working pretty neat. When I scaled it up to a 3D problem, its giving me all sorts of issues. Any comments/suggestions on the nature of solver that I can use for such a problem. I've tried different meshing options too. The solver isn't able to converge for any of those options.

Thanks,
Rohini