Giving water to baby, Too Much?
It can cause a condition called water intoxication.

Giving water to baby – bottled water or tap?
Despite the much advertised health benefits of some bottled water, they can not necessarily better for your baby.
Natural mineral water is the purest form of water, but its high mineral levels can be dangerous for babies. In particular, high levels of calcium can be difficult for the baby’s kidneys to cope. Spring water, also contain minerals and sodium and should be avoided.
Other bottled water (sometimes water table) is a more appropriate minerals and some are marked as suitable for babies. If in doubt, check with a medical professional before some water on your baby.
If you have a water bottle for your baby, keep the lid on when not in use and store in a cool place (below 10 ° C). This is to prevent the growth of bacteria. If you not all water use within one days, it is a good idea to rest before cooking it to your baby.
Also keep in mind that bottled water is not fluoridated – so if you plan to continue giving your baby once he weaned, you can talk with their doctor or dentist about fluoride supplements.
When I have to boil tap water for my baby?
There are two trains of thought on this! Some medical professionals recommend boiling tap water until baby is one years old, while others find that, after 6 months, these “over-sterilization is to contribute to the current rise in eczema and other allergies.