Actually this may depend on your water. If you have well water, I think boiling it for use would be fine. However, if your water is supplied by the city in which you live, and contains fluoride, I would boil it for only a very short period, perhaps only a minute or two. The reason for this is because boiling the water which contains fluoride only concentrates the fluoride into a salt fluoride.
A lot of so-called ‘experts’ claim that fluoride is bad for Candida sufferers, however, according to research conducted by the Institute of Preventive Dentistry and Oral Microbiology, there was only a minimal change in the Candida when exposed to fluoride, meaning no significant change in the cells of Candida albicans.