Thanks for the advice Mark,
I really would like to have Realflow, but it's Realexpensive too. The main problem with my particles is that they won't stack up. There is an example of the stacking being achieved on this site:
http://www.ksdd.com/articles/?p=14
it's about half way down the page, and you can view the video file. I can't figure out what I'm doing wrong. My particles just won't fill the cup.
Thanks