Many homes today use a water filter for their drinking water. Rather than adding a filter to your tap you can also install a whole house water filter. A reverse osmosis filter is suppose to leave the water tasting better than a traditional water filter. In a reverse osmosis filter the water is pushed through a semi-permeable membrane that removes 90-99% of tap water impurities. However a trace amount of minerals are left in the water causing it to taste better. Most bottled water is filtered with this type system. This video features on particular brand of reverse osmosis system, and explains what the filter does.