Clean water is something most of us don’t think about much—especially if we already have a filtration system installed. But that raises an important question: how do you know if your water filter is still doing its job?

The reality is that filters don’t suddenly stop working. They slowly lose effectiveness over time, and it’s easy to miss the signs until something feels off. By then, your system may not be protecting your water the way it should.

Here are some of the most common signs to look for.