If your Huntsville tap water has tasted or smelled different over the last few years, this is why. Huntsville Utilities transitioned from free chlorine to chloramine (chlorine + ammonia) as its primary disinfectant — a move many large utilities have made to comply with EPA regulations limiting disinfection byproducts like TTHMs.
What Is Chloramine?
Chloramine is formed by combining chlorine with ammonia. It's a more stable disinfectant than free chlorine — meaning it lasts longer in the distribution system and produces fewer regulated disinfection byproducts (DBPs) like trihalomethanes (THMs). That's why utilities like it.
The tradeoff: chloramine is significantly harder to remove from water at home, reacts differently with plumbing materials, and requires specific filter media to address effectively.
⚠️ Aquarium Owners: Chloramine is highly toxic to fish and beneficial bacteria in aquariums. Unlike free chlorine, it does NOT off-gas naturally if you let water sit. Standard dechlorinators that only neutralize chlorine will NOT protect your tank. You need a dechlorinator specifically labeled for chloramine removal — look for sodium thiosulfate + ascorbic acid formulas.
Why Standard Carbon Filters Don't Work Well
Standard granular activated carbon (GAC) filters — the kind in most pitcher filters and basic under-sink units — remove free chlorine very effectively. But chloramine requires a much longer contact time with carbon media, and standard GAC simply isn't efficient enough to remove it reliably.
What you need instead: catalytic activated carbon (also called catalytic carbon or carbon with enhanced surface activity). Catalytic carbon is specifically engineered with a modified surface structure that breaks the chlorine-nitrogen bond in chloramine molecules far more efficiently.
What Filters Work for Chloramine
Look for these filter types and certifications:
- Catalytic carbon whole-home filters — best whole-house solution. Aquasana Rhino uses catalytic carbon and is our top pick for Huntsville homes.
- NSF/ANSI Standard 42 certification for chloramine — check that the filter is specifically certified for chloramine, not just chlorine.
- KDF-55 media — works synergistically with catalytic carbon for chloramine reduction.
- Reverse osmosis systems — NSF/ANSI 58-certified RO systems remove chloramine effectively at the drinking tap.
Our Recommendation for Huntsville Homes
For whole-home chloramine removal paired with Huntsville's hard water, we recommend a two-stage setup: a whole-home catalytic carbon filter to address chloramine at every tap, plus a water softener to handle the 17+ GPG hardness. For drinking water, add an under-sink RO system that also addresses the 2026 PFAS concerns.