hallmark, I give bottle of water to my daugher when she up to 3 mths.
My experience is, only half/less than half amount of water than the usual milk amount i.e. my daughter eat 6 oz milk each time, I give her 2-3 oz of water (1-2 times each day)
When she grow up, increase the amount of water...
Since my daughter also mix 人奶 & 奶粉 and 奶粉 usually is "hot air' make my daughter not "boo boo" well...so i gave her water..
Now, she likes water very much...more than milk...ai....