Point-of-use water filters for home use include granular-activated carbon filters (GAC) used for carbon filtering, depth filter, metallic alloy filters, microporous ceramic filters, carbon block resin (CBR), microfiltration and ultrafiltration membranes. Some water filters use more than one filtration method. An example is a mult-barrier system. Jug filters can be used for small quantities of drinking water. Some kettles have built-in filters.
Standard Flowmatic cartridge style water filters are added to existing plumbing, the water filter cartridges are normally 10 inches long by 2.5 inches in diameter. They are made by multiple manufacturers and are available in 0.5-100 micron ratings as well as activated carbon.
While water filters help in removing many unwanted substances, it does not remove one hundred percent of it.