Chloramine is chlorine combined with a small amount of ammonia. Utilities switched to it over the past few decades because it lasts longer in the pipes and forms fewer regulated disinfection byproducts. For drinking, it is considered safe at the levels used. The catch is at home: chloramine is far more stable than free chlorine, so the filters most people buy do very little to it.
Why most shower filters fall short
The typical $20-40 shower filter uses KDF (a copper-zinc media) plus some granular carbon. Both work well on free chlorine at shower temperatures and flow rates. Chloramine needs much longer contact time with carbon than a shower head allows, so these filters reduce only a small fraction of it.
What does work
- Vitamin C (ascorbic acid) filters. Vitamin C neutralizes chloramine almost instantly, which is why water utilities use it to dechlorinate water before releasing it. Vitamin C cartridges are cheap but need replacing more often.
- Catalytic carbon. A specially treated carbon that breaks chloramine down far faster than standard carbon. It is the media to look for in under-sink and whole-house systems.
- Whole-house catalytic carbon systems for homeowners who want every tap and shower covered. Size the tank for your household flow rate.
How to read the box
Look for the word chloramine specifically, not just chlorine. For drinking-water filters, the strongest claim is certification to NSF/ANSI Standard 42 for chloramine reduction; check the certifier's listing rather than the marketing copy.
Is my city on chloramine?
Find your city below or search all cities. Utilities that use chloramine often switch to free chlorine for a few weeks a year to clean the pipes; you may notice a stronger smell during that period.