I do not like the taste of chlorinated city water so we drink bottled spring water. Near our house is a natural spring we fill jugs from it and use for drinking water at home and when we will go camping or traveling. We only use the water from holding tank in camper for showers, washing dishes,toilet, washing hands and brushing teeth. When we lived in south Florida city water was not available we had well water that had sulfur in it we could not use that in the camper because the sulfur smell would set off the alarm in camper. 

Check out the archives on this topic.  You'll see quite a bit of disagreement on the issue.  It's one of those polarizing issues that has no resolution.

We do and use bottled water. I only put potable water in the FW tank, chlorinated water. I don't sanitize, the tank has only chlorinated water in it. Should doubt arise I use the bottled water.

Ditto what Pod People said. One addition: there has never been any water added to our fresh water tank that was unfiltered either. Read that filtering was a good way to go in 2008 when buying our first RV and have never regretted following that advice...even when filling the tank at our home before a trip.