first timer--few questions

I'm planning to start my first Master Cleanse tomorrow. I'm so excited to have found this forum; it's good to know the support will be there when I need it. I do have a few questions.... Any suggestions on where to get water? I keep reading that I shouldn't use tap water due to fluoride, chlorine... I bought a case of Plenta spring water as it is free of all of these, but that is going to get really expensive if I continue. Also, you guys keep talking about P&B shakes. Are you talking about parasite and bowel cleanses? Should I be doing some of those at the same time as my master cleanse? I would love some feedback or advice. Thanks!