Don’t underestimate the importance of ensuring the purity of all the water used in your home. The worst offender is fluoride so make sure that your water supply is free from this harmful chemical. If it is not, you must take special precautions. Unlike chlorine, fluoride is not eliminated by boiling the water! The only way to get rid of it is by distillation
However, fluoride is also present in the water used for the daily shower. And although a shower needn’t take many minutes, even a brief exposure to warm water opens the pores, so that any undesirable component in the water gets quickly absorbed. There are two solutions to this problem. One is to take a sponge bath instead of a shower, in a gallon of warmed distilled water poured into a basin or sink.
The other solution is to install a camping shower in the bathroom and filling it with warmed distilled water. Full description, various models and prices of this appliance are available on the Internet.