Ultra Filtration (UF) is used to remove essentially all colloidal particles (0.001 to 0.1 microns) from water and some of the largest dissolved contaminants. The pore size in an Ultra Filtration membrane is mainly responsible for determining the type and size of contaminants removed. In general, membrane pore range in size from 0.005 to 0.1 micron. Ultra Filtration (UF) membrane nearly all of the compound will not pass through the membrane.

An Ultra Filtration filter has a pore size around 0.01 microns. A microfiltration/micron filter has a pore size around 0.1 microns, so when water undergoes microfiltration, many microorganisms are removed, but viruses remain in the water. Ultrafiltration would remove these larger particles, and may remove some viruses.

Ultra Filtration (UF) is a membrane filtration process similar to Reverse Osmosis, using hydrostatic pressure to force water through a semi-permeable membrane. Ultra Filtration (UF) is a pressure-driven barrier to suspended solids, bacteria, viruses, endotoxins and other pathogens to produce water with very high purity and low silt density.

Ultra Filtration (UF) is a variety of membrane filtration in which hydrostatic pressure forces a liquid against a semi permeable membrane. Suspended solids and solutes of high molecular weight are retained, while water and low molecular weight solutes pass through the membrane. Ultra Filtration is not fundamentally different from reverse osmosis, microfiltration or Nano filtration, except in terms of the size of the molecules it retains.