Ultrafiltration is a variety of membrane filtration in which hydrostatic pressure forces a liquid against a semipermeable membrane. Ultrafiltration produces much cleaner water than micro filtration or ceramic filtration. For example, ultrafiltration removes particles of 0.1 µm (micron) or larger, whereas micro filtration or ceramic filtration removes particles of 0.5 ~ 2 µm (micron) or larger. Ultrafiltration is effective at removing trihalo-methane (carcinogen), smell, color, pesticide, natural organic matter (NOM) which comprises trihalomethane (THM) precursors, bacteria and most viruses.
Unlike reverse osmosis filter which strips natural minerals that are healthy to human body from the water and makes the water very acidic, ultrafiltration membrane retains healthy minerals in water and does not change the pH of water. Reverse osmosis is very wasteful that 4 gallons or more are wasted down the drain for every gallon produced, whereas there is no waste when water is filtered with ultrafiltration.