A baby can drink water by the time the baby turns 6 months old.
When the baby is under 6 months old all they need to drink and should drink is the mothers breast milk or infant formula.
The breast milk or infant formula will provide them with proper hydration and nourishment until they are 6 months of age.
Once the baby is 6 months of age you can give the baby some water in their bottle.
After the baby begins solid foods then water is a good thing for them to drink but when they are on formula or breast milk then water is not needed.
If your baby is under 6 months old, they only need to drink breast milk or infant formula.
From 6 months of age, you can give your baby small amounts of water, if needed, in addition to their breast milk or formula feeds.
Don't give the baby too much water because it could be harmful until they are at least 1 year of age.
But small amounts of water is okay and healthy for the baby.