This ceramic dome contains close to 1,000,000 pores. Each pore is only 0.2-0.5 micrometers (one-millionth of a meter) in diameter. As the water is introduced to one side of the filter, any containments larger than the pore size separate from the water. These pores will separate the all following particles from your water:Three of the four common pathogens that live in water protozoa, and helminths / worms, and dominant bacteria are all removed during this first stage. Inorganic particles such as dirt and debris are filtered out during this process as well.