Is it okay to give an infant only water?

Samantha

Okay, so my father-in-law and I have been arguing about this since I had my baby. He claims that baby's need water regularly. He says too much formula is bad, if the baby is constipated to give sugar water. (well I haven't been giving my child water obviously) for example, my husbands sister has a small infant. The baby spit up his formula one day. Her father tells her that for the rest of the day to only give water. When I questioned this he said that the baby was eating too much and that no baby needs to be eating every 2 hours and deffinatly not 6 ounces not unless its 6 hours apart.... well we feed ours 4 ounces every two hours? im just wondering if this is okay or not? also, another part of their family watches my baby while at work... one night after picking her up she spit up which is normal but it didnt have any type of formula consistency it looked like plain water, should I be concerned? It seems like most people in this area have the same point of view on this subject and also alot of other old time parenting techniques like literally yesterday my co worker told me to put rum on my baby's gums for teething? Am I wrong to just be blown away by some of these things 😌😥?