Water filters have been used throughout history to improve the aesthetics and safety of drinking water. Ancient writings from India and Egypt document practices that were followed to keep water pure for drinking, such as filtering water through sand and coarse gravel. The ancient Greek physician Hippocrates believed that water had to be clean and pure; he designed a crude filter made of cloth for the water he used for his patients.
The first documented use of sand filters to purify a water supply dates to 1804, when John Gibb, the owner of a Scottish textile bleachery, installed an experimental filter, selling his unwanted surplus water to the public. This method was refined in the following two decades by engineers working for private water companies, and it culminated in the first treated public water supply in the world, installed by engineer James Simpson for the Chelsea Waterworks Company in London in 1829.
By the early 1900s, water-treatment experimentation had turned from the prevention of waterborne diseases to the creation of softer, less-mineralized water. Water softeners, which use sodium ions to replace water-hardening minerals in water, were first introduced into the water treatment market in 1903. Also starting in the 20th century, the ancient world’s ideas of personal water filtration came full circle with the advent of portable and in-home water filters that could add to the filtering process undertaken by the water provider.