Water being poured from a filtered jug.

How Often Should Water Filters Be Changed?

The reason you have a water filtration system is to avoid the consumption of harmful chemicals, right?

Therefore, you would want to look out for red flags that indicate the need for filter replacement. The job of water filters is to remove contaminants and harmful chemicals from your water before you use it. The filters protect you from lead, mercury, asbestos, cysts, harmful bacteria, pesticides and more.

When should you change water filters?

There is no straight answer to that question. Regardless of whether you have a whole-house system, under-sink system, reverse osmosis or a fridge filter system, the following matters come into play:

  • Do you use well water or municipal water? Well water typically poses higher contaminant risks and might require more frequent filter changes.
  • What is the water quality where you live? Municipal water in some areas has more pollutants, which means the filters will absorb more and need replacement sooner than elsewhere.
  • What is the filter and equipment quality? Along with water quality, the manufacturer of your filter system and the quality of the filters you use will play a role in when to replace them.
  • How often do you use it? If you have a large family, more filters will need replacement sooner than for a single or smaller family. Ultimately, the number of cups of water that have gone through the filter will determine the filter’s longevity.

Manufacturers’ recommendations

You might also want to be familiar with the recommendation of your filtration system manufacturer:

  • Whole-house filtration system:  Change the sediment pre-filter every three to six months.
  • Under-sink filtration system: Replace the filter every nine to 12 months.
  • Countertop water filters: Change necessary every three to 12 months.
  • Faucet water filters: Replacement required every three to six months.
  • Pitcher water filters: Replace the filter at least every six months.

Are there telltale signs of filters that need replacement?

There certainly are red flags to look for. If you missed earlier signs, your filtered water might reach a stage of tasting terrible and with apparent bits of contaminants floating in it. You would not want that, so look out for the following:

Some systems have electronic lights that indicate the need for new filters, typically based on how many gallons had been filtered.

If you have a whole house filtration system and you notice an unexplained drop in water pressure, and you know there is no significant water leak — the filter might be clogged up.

Odd noises from your faucets or drains could also indicate the need for a filter change. However, if you have a reverse osmosis system, such sounds are normal right after replacing the RO filter.

If you are unsure nothing keeps you from checking with the manufacturer.

Amanda Perkins

Amanda began her career as a technical writer for a healthcare group in 2008. Years after getting married and starting a family, she joined her husband Joshua on the Water Filter Authority journey to educate other families and households about safe, affordable, and effective water filtration systems.