A coffee filter, for example, separates the grains from your coffee. As water passes through the filter, the coffee grains are left behind. In reverse osmosis, however, a more concentrated solution is made less concentrated by reversing the flow. In other words, you’d be turning coffee into water by passing coffee through a special porous filter or membrane that removes the coffee.
Reverse osmosis filters utilize an electric pump to reverse the flow of water through the membrane. The process, however, can result in a lot of wasted water. For every 1 litre of clean water, reverse osmosis discards 4 – 5 litres of wastewater.
Finally, reverse osmosis can remove nitrates, salt, and limescale, but doesn’t remove all contaminants. Bacteria, for example, can get left behind.
Check out our helpful guide to find the best reverse osmosis systems of 2023.