When can I start giving my baby water ? I know not to give him much

A year old.

They get their hydration through breast milk or formula.

I think the youngest is 6 months. My daughter's says not until 8 months though, probably different for every pediatrician. But they don't NEED water until a year old. They get all their hydration from formula or breastmilk.

I always start water when I start food at 6months.