Not many of us drink tap water anymore. We either drink Spring or filtered water. Well then, so should our dogs, right?
Some holistic practitioners recommend distilled water; others consider it to be striped of the energy found in spring water.
If your budget precludes you from serving spring water to your dog, use a filter on your tap to try and screen out as many impurities and contaminants as possible. Filters are becoming cheaper and cheaper. Check out this site for a comparison and price breakdown. http://www.waterfiltercomparisons.com/water_filter_comparison.php?d=gp&gclid=CNWl5YnChqACFUuU7QodsgqlkA
Once you change from tap, you will probably notice your dog developing a shinier and healthier coat!