diluting my PCR buffer - basic question (Dec/26/2008 )

If I need to dilute a 10X PCR buffer down to 1x, can I just use water to dilute with or some special liquid? If yes, what type of water: dH2O or ddH2O? My buffer contains 150mM Tris-HCl + 500mM KCl.

ddH20 would be best.