What are Ceramic Water Filters?

Ceramic water filters are inexpensive mechanisms for cleaning water. The original design was developed in 1981 by Dr. Fernando Mazariegos in Guatemala. It was refined by Ron Rivera of Potters for Peace for mass production.

In its simplest version, which is often used in developing countries, the ceramic water filter has an outer container fitted with a spigot for retrieving the filtered water. Inside the container is a ceramic cistern made of very dense diatomaceous earth, which is primarily crushed, fossilized skeletons of diatoms, also known as one-celled algae. The cistern is filled with water from a freshwater source, which is allowed to slowly drip through the ceramic reservoir into the container with the spigot. Particles and microorganisms are filtered out during the dripping process due to the very small pore size of the ceramic material.

More expensive ceramic water filters exist as well, and are typically used in developed countries, such as the United States. These systems are similar in design concept, but modifications have been made for aesthetics. Many of these versions are intended to sit on a kitchen countertop and, therefore, are designed with some aesthetic appeal. Alternatively, these are sometimes installed underneath the kitchen sink where aesthetics are not as important. In addition, these alternate designs are often equipped with activated carbon to filter out other chemicals and pollutants, such as chlorine and pesticides.

To avoid trapping toxic bacteria in the filtering material and effectively canceling the cleansing effect of the ceramic water filters, manufacturers often impregnate the reservoir material with silver, which is lethal to bacteria and other microorganisms. The household user is instructed in the manufacturer’s directions to periodically scrub the reservoir with a scouring pad or brush. This activity sloughs off the outer layer of the ceramic material, ensuring the removal of any microorganisms not killed by the silver.

The ceramic water filters are typically used to purify household drinking water, although backpackers and international travelers often carry portable systems with them. Increasingly, small, portable systems are also being recommended for car and home emergency kits. There are alternatives to ceramic water filters, although they may filter different pollutants or filter with varying efficacy. A few alternative examples are reverse osmosis, carbon filtration, and steam distillation.