Namaste, Helen.
As I understand it reiki healing and crystal healing are two distinctly different types of healing.
That said, each can be used to enhance the other, but neither rely on the other to 'make it work'.
I must say I would be interested to know more about crystal grids, as I have known of several incidences when crystal energies have been verfiable.
Love and light jonjo. ps How' Emma?