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Filter Maintenance

February 27, 2013

EWG’s UPDATED Water Filter Buying Guide: Filter Maintenance

EWG's Water Filter Buying Guide

How to choose a filter system that meets your needs

Keep Your Water Filter in Good Working Order

All filters require regular cartridge replacement and/or other maintenance in order to remain effective. Here are four things you need to know:

FILTER CARTRIDGES HAVE A "LIFE SPAN"

  • Many types of water filters, particularly carbon filters, contain cartridges that must be replaced periodically.
  • A filter cartridge's life span, also known as its capacity, is based on the amount of water that can flow through it before it needs to be replaced.
  • Most counter-top, faucet-mounted and under-the-counter filtration systems have greater capacity than pitcher filters.
  • How often you must change cartridges, and how much they cost, greatly affects the total annual cost of any system.

WHY A CARTRIDGE THAT REACHES CAPACITY MUST BE REPLACED

  • A filter cartridge contains a material, called the media, that "traps" contaminants and removes them from the water flowing through. Those impurities remain in the filter media.
  • Once the media in the cartridge is saturated, the filter can no longer remove contaminants and is effectively useless.
  • Bacteria may accumulate in older cartridges, potentially causing more harm than good.

DIRTY OR OLD CARTRIDGES MAY REDUCE WATER FLOW RATE

  • Most filtration systems also rely on mechanical filtration to remove excess sediment and particulate matter from the water.
  • Too much trapped sediment may clog the system and lower the flow rate.
  • Depending on your filtration system, a good cleaning may solve the problem; in other cases a new cartridge may be necessary.

REVERSE OSMOSIS FILTERS AND WATER SOFTENERS REQUIRE SPECIAL MAINTENANCE

  • Reverse osmosis systems, in addition to often having one or more cartridges that must be replaced periodically, have a special membrane that must be replaced every 2-3 years.
  • Water softeners based on ion-exchange technology use salt ions to remove excess calcium and magnesium from the water. The salt gets depleted over time has to be replenished periodically.
  • Many manufacturers recommend additional regular maintenance tasks for reverse osmosis filters and water softeners. It is important to follow the manufacturers' maintenance recommendations.

Maintenance Issues to Consider Before Purchasing A Filtration System

HOW OFTEN WILL YOU NEED TO REPLACE A FILTER CARTRIDGE?

  • A cartridge's capacity, listed in gallons, is usually listed under the product description and specifications on the label, as well as in the user manual available on most manufacturers' websites.
  • Since most users do not know or track to the amount of water they use, manufacturers also suggest how often the cartridge should be replaced.
  • The lower the capacity, the more frequently you will need to change the cartridge and the more it will cost to keep your filter working well.
  • Some water filters contain a gauge of some kind that will alert you when it's time to replace a cartridge. It's unclear how accurate these are, however, so it's best to be proactive about filter maintenance.

KNOW THE COST OF REPLACING CARTRIDGES AND OTHER FILTER COMPONENTS

  • Cartridge prices can vary tremendously. To estimate your annual costs, consider both the number of cartridges you would need in a year as well as the unit cost of each one you buy.
  • In addition to any necessary filter cartridges, consider what other components of your water filter system may need replacement or maintenance. Two examples: reverse osmosis membranes and salt for ion exchange water softeners.
  • A cheaper filtration system that requires more frequent cartridge replacement may be more costly over the long term than a more expensive system.

THE FINE PRINT

  • Some filtration systems require professional maintenance services.
  • There are several different types of salts for ion-exchange water softeners. Be sure to purchase salt that is compatible with your system.
  • Consult the user manual before replacing a filter cartridge or cleaning your system!

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