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Last updated: February 27, 2026

How to Remove Chloramines from Tap Water

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Your utility switched to chloramines to reduce THMs. Now the problem is that the filter you already own might not work on it. This is a real issue, and most filter marketing doesn’t make the distinction clear.

Why Standard Carbon Fails on Chloramine

Standard activated carbon removes free chlorine through a chemical reduction reaction. Chlorine reacts quickly with the carbon surface, gets neutralized, and the water passes through clean. The same mechanism applies to most pitcher filters, refrigerator filters, and faucet-mount filters on the market.

Chloramine is more stable. The bond between chlorine and ammonia that forms monochloramine doesn’t break as easily under the same conditions. Standard activated carbon does work on chloramine, but much more slowly. At the flow rate typical for a pitcher filter or a faucet mount, the contact time between the water and the filter media isn’t long enough for a meaningful reduction.

The result is partial or inconsistent chloramine reduction. A filter that gets you from 1.5 mg/L free chlorine down to nearly zero may only drop chloramine from 1.5 mg/L to 1.2 mg/L before the water passes through. That’s not a useful result.

Pitcher filter manufacturers don’t always disclose this clearly. Some products are NSF/ANSI 42 certified for chlorine taste and odor reduction but not for chloramine reduction specifically. Both certifications fall under NSF 42. They’re not the same thing.

What Actually Works

Catalytic carbon is the right tool for chloramine. It’s physically similar to activated carbon but has a modified surface structure, typically through high-temperature activation or specific chemical treatment, that reacts with chloramine bonds more efficiently. The same contact time that does little with standard carbon can substantially reduce chloramine with catalytic carbon.

Under-sink catalytic carbon filters give you longer contact time and larger media beds than pitcher or faucet-mount filters, which makes them more effective. Look for a product with NSF/ANSI 42 certification that specifically lists chloramine reduction in the certification scope, not just chlorine.

Reverse osmosis removes chloramine and gives you coverage for other contaminants at the same time, including PFAS, arsenic, nitrates, and lead. If you’re installing a new system and want broad protection, RO is worth considering even though it costs more and wastes some water in the process.

Vitamin C (ascorbic acid) neutralizes chloramine on contact and is very effective. It’s not practical for an ongoing drinking water treatment approach, but it’s the preferred method for fish tanks and pools. Some shower filter cartridges use ascorbic acid specifically because it handles chloramine when KDF-55 alone falls short.

What doesn’t work:

  • Leaving water in an open container overnight (no off-gassing effect with chloramine)
  • Standard calcium sulfite shower filters (effective on free chlorine, not chloramine)
  • Standard pitcher filters that are only NSF 42 certified for chlorine

Step 1: Confirm Your Utility Uses Chloramines

Don’t buy a catalytic carbon filter based on a guess. First, confirm whether your utility actually uses chloramines. Not every utility does.

The fastest way is to check your Consumer Confidence Report. Every public water system publishes one annually. Look for the disinfectant type in the water quality section. It will say “chlorine” or “chloramines” (sometimes listed as monochloramine).

If you don’t have the CCR, call your utility directly. Ask: “Do you use free chlorine or chloramines as your primary disinfectant?” They’ll tell you. It’s not an unusual question.

Our guide to reading your Consumer Confidence Report explains where to find the disinfectant information.

If your utility uses free chlorine, a standard activated carbon filter is fine. The upgrade to catalytic carbon is only necessary if your supply contains chloramine.

Step 2: Choose the Right Product

Once you’ve confirmed chloramine use, the filter choice depends on what you’re treating.

For drinking water under the sink: Look for an under-sink catalytic carbon filter or a whole-house catalytic carbon system. Check the product’s NSF certification at nsf.org before purchasing. In the certification database, find the specific model and look at what it’s certified to reduce. It should list chloramine under NSF/ANSI 42, not just chlorine taste and odor.

For a whole-house approach: A whole-house catalytic carbon filter installed at the point of entry covers every tap in the house, including showers. This is the most complete solution but also the most expensive. It’s worth considering if multiple people in your household are concerned about inhalation exposure during showers.

For drinking water in a pitcher: Most standard pitcher filters don’t use catalytic carbon. Clearly Filtered and Aquagear use filter media that addresses chloramine more effectively than standard Brita or ZeroWater media. Check the specific product’s chloramine reduction claim and whether it’s backed by NSF certification or documented third-party lab testing.

An RO system is the most thorough option for under-sink drinking water. Our best under-sink RO systems page covers what to look for.

What to Do About Shower Water

Chloramine exposure during showers is a concern for two reasons. First, chloramine is volatile enough to release into the air during a hot shower, and some people with respiratory sensitivities report irritation. Second, skin contact during a long shower adds up.

The challenge is that most shower filters on the market use calcium sulfite as their primary media. Calcium sulfite works well on free chlorine. It’s much less effective on chloramine. If your utility uses chloramines, a standard calcium sulfite shower filter won’t do much.

For chloramine reduction in shower filters, look for one of three media types:

  • KDF-55: A zinc-copper alloy that works through redox reactions and handles chloramine better than calcium sulfite
  • Vitamin C (ascorbic acid): Neutralizes chloramine on contact, highly effective, but cartridges exhaust more quickly
  • Combination media: KDF-55 plus catalytic carbon in a two-stage design

Before buying any shower filter claiming chloramine removal, check whether it’s NSF/ANSI 177 certified. NSF 177 covers shower filtration devices, and the certification should specify whether it covers chloramine, free chlorine, or both. A product that’s NSF 177 certified only for free chlorine is not going to perform on chloramine.

Our best shower filters page covers options with documented chloramine reduction separately from those that only handle free chlorine.

After you’ve installed a filter, test it. A chloramine test strip or drop-based test kit from a pool supply store can tell you whether your filtered water still has measurable chloramine. If it does, either the filter isn’t working or the contact time is too short.

For background on why utilities use chloramines, the lead pipe connection, and the health research, see the chloramines contaminant overview.

Sources

Frequently Asked Questions

What is the most effective filter for chloramine removal?
Catalytic carbon is the most practical option for most households. It's a form of activated carbon with a modified surface that breaks chloramine bonds more efficiently than standard carbon. Look for filters specifically certified to NSF/ANSI 42 for chloramine reduction (not just chlorine reduction). Reverse osmosis also removes chloramine and is a good choice if you want broader contaminant removal.
Does vitamin C remove chloramine from drinking water?
Vitamin C (ascorbic acid) neutralizes chloramine on contact and is very effective. It's the preferred method for filling fish tanks and pools when you don't have a carbon filter. For household drinking water, a catalytic carbon filter is more practical than dosing with vitamin C continuously. Vitamin C is commonly used in shower filters designed for chloramine removal.
Can I remove chloramines from shower water?
Yes, but you need the right filter. Most shower filters use calcium sulfite, which removes free chlorine but is much less effective on chloramine. For shower chloramine reduction, look for filters using KDF-55 media or vitamin C (ascorbic acid) cartridges. Some filters combine both. Check the product's NSF/ANSI 177 certification and confirm it lists chloramine removal, not just general chlorine.
Will leaving water out overnight remove chloramines?
No. Free chlorine off-gasses when you let water sit in an open container. Chloramine doesn't, at least not meaningfully within 24 hours. Don't rely on this method if your utility uses chloramines.
How do I know if my filter is working on chloramines?
The most reliable method is a water test. A chloramine test kit or test strip can measure residual chloramine in your filtered water. The result should be near zero if your filter is working. Drop-based test kits (the kind used for pool water) are reasonably accurate for this purpose. Retest every few months and after filter changes.