well, this guy finally became to aggressive to be part of a community....so I have set him up a tank all to himself, he is around 8-9in....I have not decided yet what to use as substrate (most likely fine gravel) and need to add a bit more decor....but anyway this is his new "castle" 
[video=youtube;lgu0yDW1bzo]http://www.youtube.com/watch?v=lgu0yDW1bzo[/video]
[video=youtube;lgu0yDW1bzo]http://www.youtube.com/watch?v=lgu0yDW1bzo[/video]