South Florida water has fluoride and chlorine in it. Plus, there are documentaries about all the medications flushed down the toilet and sink and how the filters (across the nation, not just in FL) can't take it all out.

I don't need the fluoride (which may cause other problems) and I'm a bit allergic to chlorine, and highly allergic to medications (even have issues with hormones and antibiotics in meat products). I don't trust the bottled water to be "really pure" (some are just tap water from some other city) and I have issues about things in plastic (as I'm also allergic to petroleum based products) ... so I use a filter. Even the dog prefers that water!
[wow I am high maintenance aren't I ? )

Bottled water is just so expensive! I mean, the world takes the cheapest thing we have, and makes it profitable.