no no no no ... dont use plaster of paris. dolomitic limestone is usually available
at garden stores. it is an off white with bits of darker stuff in it. make sure it
has no other additives. Ingrid

On Wed, 13 Feb 2008 02:42:44 GMT, "Richard Brandstetter"
wrote:

Thank you fore the reply .
I think I will used a plaster of Paris chunk