Question:
you can find posts on the internet to prove just about anything. I just did a quick test with my water and my brita filter and there was almost no change in hardness, maybe 1/2 a dGH and 1/2 dKH, probably due to those salts made of heavy metals that exist in my water supply. BTW, I took a couple of classes in college that dealt with surface chemistry, so I actually understand the processes involved in filtering with activated carbon and ion exchange resins. None of which filter out carbonates, you need a semi-permeable membrane for that.

Answer: The original ad campaigns for the Brita emphasized its ability to improve _taste_ by removing not only chlorine but by reducing the hardness as well. Hence the comparison within the posting Rob dredged up to "on the box claims". The thrust was toward better, "cleaner"-tasting water for your coffee and tea as well as simple drinking.

However, then came the round of NFS certifications and an increasing public awareness of what actually constituted water "quality". Seizing a marketing opportunity, they simply changed the focus of their advertising towards something that appealed to the general consciousness.

But Brita is no different than any of the other manufacturers. When it comes to water purification - especially where organic compounds are concerned - it's rather easy to deduce the source of most of this capability. Try the info at

http://www.resintech.com/Content/TechArticles/Activated%20Carbon%20Fi... n.pdf

all of which should be on a single line if word wrap munges up the addy.