I totally agree with blood raven, some billboarded glows would be nice - also, i think you should add a "flat" emitter at the bottom of the stream where lava-like particles float outwards (use "XY quads" to make your particles billboard to z-axis only), use a texture like "textures\roman1" or similar. Optionally, you could add some small particles coming out of the tube to give more motion (just add some gravity to them and make their initial speed slow enough to match the flow). This would make the stream come alove more. Right now it just looks too flat.