Buying Guide

Types of Water Filters

Types of Water Filtration Systems
Description Feature/Benefits
whole house water filters A whole house water filter connects to the main water supply line within the house and filters all water throughout, including faucets, showers, washing machines and dishwashers. Available filter types include pleated, poly spun and carbon wrap. Cost-effective method for filtering all water in the house to improve the overall quality.
reverse osmosis systems Filters water through a very fine, semipermeable membrane to remove contaminants. Provides bottled water-level water quality. A popular filtration technique used in water purifiers. Often used in conjunction with carbon filters. Slower filtration process. Creates around 5 gallons of wastewater for every 1 gallon of filtered water. Requires regular cleaning and filter replacement.
under sink water filters Installs below the sink and filters water before it reaches the faucet. Filters water going to a specific faucet. Filter cartridges tend to last longer than the faucet-mounted variety. May have multiple filter cartridges designed to remove specific types of contaminants.
countertop water filters Screws onto faucets so you can quickly filter large amounts of water without installing new plumbing. Hose attachment diverts water from your faucet through the filter and back to the tap. Easy to install but takes up countertop space.
faucet mounted filters Treats water as it passes through the faucet, improving it for drinking, cooking and washing. Require no plumbing connections. Economical and easy to install. Take up little space.
water filter pitchers Uses a carbon filter to reduce contaminants from water. Sizes range from around 8-cups to a gallon. Easily portable. Economical and easy to maintain. Take several minutes to filter water.
refrigerator parts & water filters Provides filtered water for ice makers and in-door water dispensers in refrigerators. Some include an automatic shutoff valve for easy replacement. Use charcoal filters. Included in some new refrigerators.
shower filters Reduces chlorine, bacteria and fungus in the shower head. Compact, flexible design installs easily in most showers.
Water Filter Contaminants
A water testing kit with color coding shows levels of contaminants in water.

Find the best water filter to eliminate specific contaminants. A water testing kit can help identify condtions and contaminants present in your tap water. Find the best water filter to eliminate specific contaminants. 


Bacteria filters

Not all types of bacteria are harmful but pathogenic bacteria can make you sick. Harmful bacteria can enter your water supply from runoff, a fractured well casing or broken lines. 


Chlorine filters

Chlorine is often used in municipal water treatment to disinfect the supply. Leftover chorine compounds coming from your tap can cause dry, itchy skin and also have an unpleasant taste and smell.


Copper filters

Copper is an essential element found in rock, soil and water. Corrosion of copper pipes in your home can boost the concentration found in your water. Ingesting water containing high levels can cause gastrointestinal issues. 


Fluoride filters

Fluoride is added to most public water supplies to reduce tooth decay throughout the community. Too much exposure to the natural mineral at a young age might increase risk of a cosmetic condition that causes dark streaks or spots on teeth.


Iron filters

High levels of naturally occurring iron in your water produces a metallic taste and smell. It can stain your toilet, sink, bathtub and even the dishes and clothing cleaned using the water.


Lead filters

Lead usually gets into a water supply by leaching from lead service lines or other parts of the plumbing system, such as the lead solder for joining copper pipes or even brass and chrome-plated faucets. Young children and pregnant women are particularly vulnerable to adverse health effects from lead.

How Water Filters Work
Three clear glasses containing water at various stages of filtering.

Consider how water filters work when determining which is best for you. Different types of water filters use a variety of methods to remove or destroy contaminants.


Ultraviolet light

Water is exposed to ultraviolet radiation from UV filters and destroys various bacteria that could be potentially dangerous to your health, without using additional heat or chemicals.


Carbon block/activated carbon filters

Carbon filters remove larger particles from water by attracting and absorbing sediment or silt. This method is perhaps the most common and found in many types of water filters, including faucet water filters.


Sand/sediment mesh

Mesh filters can remove dirt, clay, sand and rust particles before they reach the rest of your plumbing system, including expensive appliances – and your faucet.


Reverse osmosis

A reverse osmosis water filter forces water through a semi-permeable membrane. This removes contaminants and impurities from drinking water. 


Infrared filters

Infrared technology uses heat and light to negatively charge hard water. As with alkaline filters, the water treated with an infrared filter has a softer feel.


Alkaline/Water ionizers

Water passes over electrically charged plates, separating the alkaline water from the acidic water. The result is softer water that is more suitable for drinking and also is better for your skin when bathing.


Read manufacturer’s labels carefully to determine what contaminants are removed from the water filtration system. Not every method of filtration will remove all contaminants to purify water.