Water filters are different from water purifiers because water filters rid harmful bacteria and protozoa through microfiltration. Water purifiers not only use microfiltration, but also chemical treatments that eliminate harmful bacteria in more depth. Water filtration systems are necessary regardless of how the water may appear from the outside. Especially in more populated areas, water contains microscopic pathogens that can harm the body and give symptoms such as diarrhea, vomiting, fever, etc. To prevent any of these harmful side effects, certain filters are created for different uses. These filters include bag filters, industrial filter, filter presses, bed filters, and cartridge filters. Here is a description of what each filter does and where they best serve their purpose.