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How Do Water Filters Work?

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As you consider water purification options for your home, you may be curious how water filters work at getting your water sparkling clean. Water filters come in many different styles, and some total filtration systems include water softening techniques as well. In order to understand how water filters work, you must start at the basics and work your way up. Essentially, water filters separate particulates and contaminants from water molecules. How they do so depends on your filter's model and the methods you choose.



Sand filters are among the most primitive styles, but they work well. As water passes through the sand particles, the smooth water molecules easily work their way through the filter while contaminants and other particulate matter get trapped among the microscopic sand granules. Most modern water filters do not use sand alone, but you may encounter sand filters in some older homes.


Filters using carbon or activated charcoal are among the most common models for homes today. These filters have a high surface area that traps chemicals like chlorine and other particles that affect the color, odor and flavor of your water. Carbon filtering is an inexpensive method that takes care of nearly all chemical and flavor issues associated with your water supply. It doesn't clear your water of mineral deposits, however, which is why it is also useful to own a water softener.


Reverse Osmosis

You’ve likely noticed your reusable water bottle touting “reverse osmosis” filtering and wondered what that means. Reverse osmosis is a pressure-based system that actually has applications in converting saltwater to drinking water. This works by pressurizing your water until it passes through a semi-permeable membrane. The pure water molecules pass through easily, while the heavier contaminant particles stay behind. This process is very effective at producing clean and safe water.



Though not exactly a filtration method, water purification tablets are also used to clean water and neutralize bacteria and contaminants. Since many tablets use chlorine and iodine to kill bacteria and purify the water, you may find that your water tastes slightly like those chemicals, but it's safe to drink when a proper filtration method is not available.


As you choose your water filtration method, consider the cost and level of purity you want. Tablets are the cheapest, but they won’t be as effective as a reverse osmosis system. The right filtration method will ensure that your water tastes delicious and refreshing every time.


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