A: Matt, you're right to give your children water to drink instead of soda. Most studies have found that bottled water and tap water are equally healthy. In fact, although bottled water may be advertised as mountain spring or glacier water, most bottled water comes from a municipal water supply. In other words, most bottled water is just tap water. Few bottled waters actually come from mountain springs or glaciers.

In general, tap water is very healthy and safe. Tap water is strictly regulated by the U.S. Environmental Protection Agency (EPA) and closely monitored by the municipal water supplier. In most areas of the United States, tap water also has added fluoride, which is important for children because it helps reduce tooth decay.

Bottled water is less regulated. Most bottlers belong to the International Bottled Water Association with voluntary guidelines. Some states have regulations and others do not. Bottled water that is imported or shipped across state lines is regulated by the Food and Drug Administration (FDA). Although studies have found that most bottled water is safe, some have been found to have contaminants such as bacteria and other dangerous chemicals. In addition, most bottlers filter out the fluoride, so children drinking only bottled water would need to take fluoride supplements to protect their teeth.

In general, then, it's healthiest and cheapest to give your children tap water. There are some instances, however, when bottled water is recommended: if your water supply is from an unregulated private well and in developing countries where the water supply is more likely to be contaminated. In addition, on the rare occasions when the municipal water supply may be contaminated (such as after a flood) or if your water is high in lead from your plumbing pipes, public health authorities may recommend filtering your tap water or drinking bottled water.