DW bought some new PUR water filters again the other day. I asked her how long they usually last and she said the manufacturer recommends that they be changed very 2 months. I thought that was interesting, as I would think that their useful life would not be measured in time but in usage, say gallons filtered.
So, I’ve done some research and it looks like a typical PUR filter can filter 40 gallons of water. Now, that makes sense to me! Given our usage of filtered water, a filter should last the two of us about 4 months.
Just saved 50% on PUR filters.
Much depends on what you want to remove and the quality of your water. This list gives some idea of what they control but they have several different models.
Most of the things listed are probably absorbed by granulated carbon (aka activated charcoal). The metals are probably removed by ion exchange. Both have a specific capacity depending on what is in your water.
Off taste and odor is the one easiest for you to detect. The others would require chemical analysis. My water company provides typical numbers once a year or so or on request. And the numbers can vary with season (dead leaves in the water, etc) and sometimes winter/summer changes in water source. Of course drought and flooding are variables.
My PUR Filter comes with a transparent “window” of their remaining usefulness and when it reaches that point the filter will no longer dispense water. Starts out as clear, and indicator turns white as it progresses across the window, finally to red and then stops dispensing. As mentioned, a lot depends on your local water conditions & how much you use it.
For me, its my secondary filtered source used mostly for cooking. I use a Zero water filter for drinking, coffee, etc.