I purchased this setup a month ago because the water tastes awful. This 30 cup capacity claim is a stretch to say the least. Unless you bypass the filter as a whole you will never fill up the pitcher. The top half will just stay borderline full and only filter once you remove some of the water from the pitcher. So the 30 cup capacity claim is probably a combination of the max that the filter will allow the bottom half to fill and the top tray at max. I left mine out for an entire day trying to fill up the base and it never goes past a certain point. Does the filter do a good job? Yes, is it worth getting the large capacity one? Not at all.