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!