The most popular kind of pur water filter by far are activated carbon filters that make used of burned coconut husks in order to clean water. For most intents and purposes, these kinds of filters are quite adequate, and can be pretty effective especially when paired with nano-silver components, which have an anti-bacterial property. These kinds of filters are among the easiest to install and maintain and refills may be needed only around twice a year. However, you may want to learn more about the other types of filters before you make any decisions on a model of filter to purchase.