Types of In-Home Drinking Water Filtration

tap water

tap waterChoosing the right type of drinking water filtration for you and your family is important, however, this choice can sometimes be difficult as there are multiple types of drinking water filters available on the market.

Since the quality of tap water available varies by location, the water filtration needs for each household are different. So before selecting a filter, it is best to know the most common types of contaminants in the tap water in your local area. An easy way to find out what is in your local tap water is to reference your annual Consumer Confidence Report (CCR) from your water supplier or to look up your local area in the Tap Water Database from The Environmental Working Group (EWG).

Types of Filtration Methods

After you have a better understanding of what contaminants you need to remove from your drinking water, selecting the best type of water filtration for your home or business is easier. Here is a brief overview of the three most common types of filtration methods used in home drinking water filters.

Activated Carbon

Activated carbon is used in nearly all in-home drinking water filters because of its effectiveness in removing chlorine, taste and odor, man-made chemicals (e.g. insecticides/pesticides), and volatile organic compounds (VOCs). Activated carbon filters water use adsorption, which chemically bonds the contaminants to the outside surface of the carbon, removing them from the water.

Ion Exchange/Deionization

Ion exchange resin is used in some in-home water filters to remove total dissolved solids (TDS). The TDS in the water is exchanged for hydrogen and hydroxide ions as the water passes through the ion exchange resin. The TDS bonds to the resin and the hydrogen and hydroxide ions combine, forming water molecules.

Reverse Osmosis

Reverse osmosis uses water pressure to force water through a semipermeable membrane. The 0.0001 micron pores (holes) in the reverse osmosis membrane prevent the impurities and contaminants from passing through with the water molecules. The filtered water flows to a storage tank and the contaminants are flushed out of the filter as wastewater to an attached drain. Reverse osmosis will remove common chemical contaminants including sodium, copper, chromium, lead, arsenic, nitrates/nitrites, sulfate, calcium, magnesium, selenium, fluoride, radium, barium, cadmium and total dissolved solids (TDS). It is also highly effective in removing protozoa, bacteria, and viruses (e.g. Cryptosporidium, Giardia, E. coli, Norovirus and Rotavirus).

Types of In-Home Drinking Water Filters

Each type of drinking water filter requires a certain level of maintenance based on the average lifespan of the filters. When choosing the best type of drinking water filter for your household, make sure to consider what contaminants each filter can remove from your water and the maintenance required.

Faucet Water Filters

Faucet water filters are small and install directly onto the spout of an existing kitchen faucet. Since these filters are installed directly onto the faucet, they allow for access to filtered water or unfiltered tap water through your kitchen faucet. Most faucet water filters use activated carbon as the filtration method, although some also offer ion exchange filtration. Activated carbon filters remove chlorine, many insecticides/pesticides, volatile organic compounds (VOCs), taste and odor. Activated carbon does not remove minerals, heavy metals, salts or total dissolved solids (TDS). Faucet water filters with ion exchange resin can reduce TDS.

  • Filtration Type: Activated Carbon or Activated Carbon and Ion Exchange
  • Typical Filter Lifespan: 3 Months/100 Gallons

Water Filter Pitchers

Water filter pitchers require no installation as they are stored in the refrigerator. Water filter pitchers require manual refilling as water is used, as they are not connected directly to your tap water. Similar to faucet water filters, water filter pitchers include activated carbon filtration, however, some multi-stage pitchers also include ion exchange filtration. Although the filtration methods are similar to faucet filters, pitcher filters are larger and typically contain multiple stages of activated carbon and a larger amount of ion exchange resin.

  • Filtration Type(s): Activated Carbon or Activated Carbon and Ion Exchange
  • Typical Filter Lifespan: 1 Month/40 Gallons to 3 Months/100 Gallons

Fridge Filters

Internal refrigerator filters are connected directly to your household cold water supply and use activated carbon filtration. Just like faucet and pitcher water filters, the activated carbon removes chlorine, insecticides/pesticides, VOCs, taste, and odor.

  • Filtration Type(s): Activated Carbon
  • Typical Filter Lifespan: 6 Months

Reverse Osmosis System

A reverse osmosis (RO) system is typically installed under your kitchen sink and features a storage tank and faucet for on-demand access to filtered water. A RO system is connected to your under-sink cold water supply and kitchen drain pipe, so it can automatically filter water to ensure the storage tank is always full. When compared to the other types of in-home water filters, a RO system removes the largest number of contaminants from tap water. RO systems can also be connected to provide filtered water to multiple outlets, such as a refrigerator water and ice dispenser, which eliminates the need for internal fridge filters.

A RO system has a sediment filter to remove sand, silt, dirt, and rust and multiple activated carbon filters to remove chlorine, man-made chemicals, VOCs, taste, and odor. The reverse osmosis membrane removes common contaminants including sodium, copper, chromium, lead, arsenic, nitrates/nitrites, sulfate, calcium, magnesium, selenium, fluoride, radium, barium, cadmium and total dissolved solids (TDS).

  • Filtration Type(s): Sediment, Activated Carbon, Reverse Osmosis
  • Typical Filter Lifespan(s): Sediment and Carbon Block (Stages 1-3): 6-12 Months, Reverse Osmosis (Stage 4): 2-3 Years, Post Carbon (Stage 5): 1-2 Years