I installed a Watts RO Pure reverse osmosis system in March 2009. We use the filtered water for drinking, brewing beer, making coffee, and much of our cooking. Watts recommends changing the sediment and pre-carbon filters every 6 months, the post-carbon filter every 12 months, and the reverse osmosis filter every 3 years (or as needed). So while changing the filters last October, I cut apart the filter housing to see what is responsible for filtering our water. The pre-carbon filter broke when I hit the housing unit against a concrete floor repeatedly, but I suppose that's to be expected. I'd also be curious to know if the material used in the sediment filters are white to begin with. I plan to take apart the reverse osmosis membrane, but that's scheduled for March 2012, so you'll have to wait. Here are the pictures I took, you can click on them for a larger version.