Water Filtration Pitchers - How Long 'Till Filter is Actually Dead?
 

I bought a Pur pitcher last June. I'm still on the same filter, though it's slowed down considerably. Is it even still filtering? It sure seems to be. The recommended time to change is three months. Those things are expensive and unless there's some compelling reason to toss it, I'm keeping it until no water passes through it.

How long to you keep yours in before changing it?

The slower filtering is probably due to the charcoal packing down with gravity. If you remove it and rock it back and forth, it may 'unpack' the charcoal bits and it will flow faster. Frequency will vary depending on the minerals in your water, but I change my Brita filter every three or four months.

When the work water wasn't really drinkable unless it was filtered, I would change the filter whenever it started getting that metallic taste again. I never put much faith in the 3 month thing, if I was pouring it all day there's no way it could be expected to last as long as if I was using it once every few days.

When home, I go through a couple pitchers a day, so maybe ~10 or so pitchers a week. I'll try shaking it up. I had thought it's the contaminants clogging the filter. The above explanation makes more sense.

Seriously, if you have particles in your water that are clogging the filter, and it's not like iron from your own well, you got way more problems than a counter filter will take care of and should consider a much different solution.

Next time you change it, cut the old one open (outside, it will make a mess) to see what's in it and you will understand how it can be packed down.

Look for duPont filters, they make a model that fits pur and brita pitchers and is 1/3 the price for same quality :D

I personally use the double filter model of their own brand at home, and I have a ZeroWater in my office, the ZeroWater is alright now sure I'd buy again.

Well, yeah, I know one single particle is not going to clog the filter, but months of use can build up some scale and cause a clog, no? Then again, I am drinking Charles River Cocktails, so ya never know what's in there! ;)

I'll look for the DuPont filters.

duPont...don't they make paint or flooring? Anyway, I think I remember seeing a review somewhere comparing the different filters and their results. Brita had the best numbers.

As far as how often to change your filter, it's not so much how long (time), but how much water (quantity) you run through it. They say to change it after filtering 40 gallons.

I've had a Brita filter. To me, it adds an unnatural sweetness to the water. Didn't like it. I do, however, like the Pur filter. Just personal preference.

As far as 40 gallons, who came up with it and how? Sorry but I'm a cynic and say it's just some bean counter's number to say when I should replace the filter. That is until I see some scientific results or other unbiased opinions, which is exactly why I started this thread.

The only way you will see anything worthwhile is if you have your water analyzed. That is the raw water, and the filtered water at 1 gallon, 10, 20, 40 etc. Similar to what you do when you install a whole house system. The levels of contaminants in your particular water determine how often the system must backflush/rejuvenate (or in your case, replace). 40 gallons might be average for your pitcher, but if your water has a lot of crud in it, or a lot of a certain type of crud, the filter's ability to trap it may cease at 20 gallons while another user could go 200 gallons.

duPont is a bit of a conglomerate.
http://www2.dupont.com/Water_Filtrat..._US/index.html

GAC (granular activated carbon) filters have pretty predictable lifespans. filtration is normally 99-100% effective until the end of that lifespan, at which point passthrough quickly becomes almost, or as, high as with no filter at all. most commercial filters have an average lifespan slightly longer than advertised (e.g., if they say 40 gallons, then the true lifespan is probably 45-50) in part because people tend to use them a little longer, and in part because the rated lifespan is an average (meaning that sometimes the filter's actual lifespan will be around 40-43, for example).