Contrary to popular belief, water filters don't actually run on magic and disposable plastic. However, they're actually very easy to change out, and for much less than the sticker price that comes along with the Britta name.

Instructables user IAMSatisfied shows in the video above how to cut open a single water filter (the only one you'll need to purchase) and refill it with fresh activated carbon. The key ingredient that actually does most of the filtering is extremely cheap and the disposable filter can be modified for repeated refills, potentially saving a fortune over the long term.

How to refill a "disposable" Brita brand water pitcher filter with activated carbon | Instructables via WonderHowTo