Clever mom! ^^, Just keep on it! 80% of our body is water, think about it, spring water is healthy for a reason, it has all natural things for your body that you need, like calcium, its a great source. Tap water is like drinking death xD
How do you think they discovered that fluoride is good for your teeth? Just take a wild guess.
You know, there are a lot of places in the world where they don't have to worry about that deadly clean drinking water. They're lucky, aren't they? Of course the most common cause of death in children in those places is infectious diarrhea, but at least they don't have to worry about their pineal glands getting calcified. (You know, pineal glands have been getting calcified for a lot longer than they've been adding fluoride to water. That's brain sand; it's always been there.)
I guess people who don't have real problems need to make shit up to worry about. Of course, they may just not know what their real problems are yet. Lol, I must have too much free time too, the discussions I've been having lately.