Even though my tap water tastes ok, I give Oscar filtered water just in case. Without having the water analyzed it would be hard to know what is really in it. I have a filter that attaches to my tap, and a pitcher filter that I keep in the fridge. (Both by Brita, I think).
I prefer the filters to bottles for environmental reasons. I also read an article that claimed that bottled water is actually pretty unhealthy due to its natural erosive properties ... according to the author, it microscopically breaks down the inside of the water bottle and we end up drinking dissolved plastic.
Congrats on your new baby and welcome to YT!!! The puppy stage is a ton of work, but really special too. Post pictures when you get a chance.
