Reverse osmosis is an amazing technological innovation that converts seawater into drinking water in areas around the world where freshwater is in short supply. It's also highly effective at cleaning contaminated wastewater in industrial settings. It can be a good option for household water under certain circumstances (e.g. kidney failure). However, in most cases mains water is safe to drink, and a high-quality activated carbon tap filter will give you great-tasting drinking water at a lower cost and with less