Thanks guys. I was making a sort of dry ice smoke. I had a -9.8 gravity and a volume field blowing it up and out of my container grate holes. Velusion, I'm pretty sure I had all the settings you mentioned tuned correctly. But until I made the voxel size smaller than the holes, the particles didn't escape. Also, at low resolution, the fluid would show through the walls of my container. My concept of fluid collisions is that the voxel size also determines the geometry bounding box resolution. Am I confused? I also struggled with particle lifespans. It seems fluidEmitter particles don't have this, only dissapate. Is that right?