The lifespan of a filter largely depends on the type of filter. Most hollow fiber or activated charcoal cartridges will need to be replaced every couple hundred uses, or after a certain number of liters have been filtered. Some filters, like the LifeStraw, can last for years, but when it’s run its course you’ll need to buy a new one.
There are also some filters and purifiers that just need new batteries or to be charged.
A filter can last you many years if you take proper care of it; (photo/Emily Malone)