Product review (5 stars): Filters are so important
I live in Amarillo, TX and we are known for some of the worst tap water in the country.  It's loaded with minerals.  If you look at a glass of tap water, it's cloudy white - gross.  That's why this filter is so important since my refrigerator has a water dispenser.  Not only do my wife and I drink from it, but my dogs do as well.  Your refrigerator will have it's own system for alerting you when to change the filter, but it's based on a stretch of time, not on the actual filter's condition.  So I almost always change my filter out every other month.  I recommend you do the same if you live in an area with terrible tap water.