While practices vary among parents, many pediatricians recommend boiling your RO or UV-filtered water for the first 6–8 months of life to ensure it is completely sterile. Even if you use a high-quality home filtration system, boiling provides an extra layer of safety for an infant's sensitive digestive system, especially since stored filtered water can potentially harbor bacteria. Most parents find it easiest to boil a fresh batch each morning, let it cool, and store it in a clean container for use throughout the day.