There's chlorine in your drinking water, America. Hence, water filters like WIRED's best-tested shower filter, the Canopy Filtered Showerhead, designed to remove chlorine before you wash with it. But if you do buy filters for your drinking water or shower water, there's a complicating factor. If you're trying to filter out chlorine compounds, it matters which one your city is using. But chloramine's relative stability can also make it harder to filter out of water than pure chlorine, especially using shower water filters that rely on chemical reactions to neutralize chlorine.