Disinfectants
Chloramine vs chlorine in tap water
Chloramine is chlorine combined with ammonia. Utilities use it because it stays in the pipes longer. That same stability makes it harder to take out at home.
| Chlorine | Chloramine | |
|---|---|---|
| Fades if water sits | Yes | Not quickly |
| Boils off | Yes | No |
| Standard carbon removes it | Yes | Very little |
| Catalytic carbon removes it | Yes | Yes |
In the Bay Area
The SFPUC’s Hetch Hetchy system switched to chloramine in February 2004. See which supply reaches you.
Dialysis patients: the EPA says chloramine must be removed from dialysis water. Talk to your care team.
Sources: EPA, SFPUC treatment process, NSF.
These are published ranges and general guidance, not quotes. In the Bay Area, Soft Patagonian offers free water tests.
Common questions
Does boiling remove chloramine?
No. The EPA notes chloramine does not dissipate quickly on standing and does not dissipate by boiling.
What removes chloramine from water?
Catalytic carbon is the usual whole-house option. Look for a filter with an NSF/ANSI 42 chloramine reduction claim.
Does chloramine matter for fish tanks?
Yes. The EPA says chloramine is toxic to fish and amphibians at drinking water levels, so aquarium water needs a treatment product that handles it.