Re: Kidneys and water fasting
Just find out if there is anything added to your tap water, the obvious things to look for are chlorine and fluoride. Mostly when people brag about the quality of their water they are defending it's safety to drink in my experience. The water can come out brown and in some cases they will still brag about it. So it's worth investigating. If the tap water is no good just find a cheap bottled or cask water in the supermarkets. Here they have one that is completely pure very cheap in ten litre casks. But even spring water in a bottle would be better in many cases than tap water with chemicals added. So a bit of research is well worth the effort.
With one kidney I'd suggest the main thing to watch is not to drink too much, be very careful to stick to only having the water your body needs and not overload it with what it doesn't. I'm not suggesting dry fasting (for once!) either, just take your water in small amounts and monitor your output and listen to your body. Unless you can get specific advice from someone else who has fasted with one kidney you may have to be your own guinea pig in this matter, but as long as you listen to your bodies needs you will be fine, it will certainly let you know if it is in distress.
The main thing to remember is your kidney functions well enough on it's own while you are eating and it will continue to do so while fasting, and will benefit from the fast the same as the rest of the body will.
Take care and good luck,
Andrew.