Steriliser. Tap water is fine. There is a heating element that brings the water to a boil, causing it to release steam and hence, steam everything within the steriliser/steamer. You will need to check the manufacturer’s instruction on how to clean the element - it gets a bit black/dirty over time, so good to clean it every month or so. Ah… which reminds me… I have a pack of Mothercare steriliser cleaning solution - PM me if you are interested.Re feeding: The current recommendation is that all babies are breastfed or formula fed for the first 6 months. This is to allow their intestines and digestive system to grow and mature. In some cases, however (e.g. if babies are not taking milk well), the pediatrician will instruct the parents on how to add some other food - rice cereal, puree, etc … otherwise, please, do not be in a hurry (or listen to some old auntie’s advice) about introducing porridge/cereal to young babies.