Chlorine is what most people are tasting when they say the tap water is unpleasant, and it is the easiest common target to treat: activated carbon reduces it readily at modest contact time. The complication is chloramine, a longer lived disinfectant many utilities have switched to, which behaves completely differently in a filter and defeats equipment sized for chlorine.
Find out which disinfectant you actually have
This is the question that decides the equipment, and it costs nothing to answer. The EPA notes that every community water system publishes an annual Consumer Confidence Report and maintains a finder for them; that report names the disinfectant in use. Utilities also switch seasonally, and some run chloramine most of the year with a chlorine burn for a few weeks, which is why a filter that has always been fine can suddenly stop keeping up. If the report says chloramine, size for chloramine and stop comparing chlorine performance figures between products.
Standard carbon for chlorine
Chlorine is reduced by ordinary activated carbon through a fast surface reaction, so almost any properly sized carbon stage will handle it: a faucet cartridge, an under sink block, a pitcher, or a whole house tank. The practical questions are flow rate and capacity rather than whether it works. Whole house units keep chlorine out of showers and laundry as well as the kitchen tap, which matters to people who notice it on skin and hair, while a point of use filter treats drinking water alone for a fraction of the media cost.
Chloramine needs catalytic carbon and time
Chloramine is chlorine bound with ammonia. It is deliberately more stable so it persists through the distribution network, and that stability is exactly what makes it hard to remove. Standard carbon reduces it slowly and incompletely. The answer is catalytic carbon, a modified media with a surface that drives the reaction, combined with substantially longer contact time, which usually means a bigger vessel or a slower flow than the same house would need for chlorine. A whole house unit sized on a chlorine rating will under perform on a chloraminated supply.
Where to put the filter, and what else it changes
For taste alone, at the kitchen tap. For skin, hair and laundry as well, at the point of entry. A whole house carbon filter has a useful side effect worth knowing: removing the disinfectant residual means the water inside the house plumbing is no longer protected against bacterial regrowth, which is a reason to keep filters changed and, on some systems, to leave the run to the house short. Our whole house water filter guide covers sizing, and our shower filter guide covers the point of use option.
Questions people ask about water filter to remove chlorine
Does a carbon filter remove chlorine completely?
It reduces it to the point where taste and smell are gone, which is what people mean in practice. Complete removal down to nothing is not the standard being measured.
How do I know if my water has chloramine?
Your utility's annual Consumer Confidence Report names the disinfectant. The EPA maintains a finder for those reports, so no test is needed.
Will boiling get rid of chlorine?
It drives off free chlorine over several minutes but does not deal with chloramine, and it is not a practical way to treat a household's water.
Does removing chlorine make water unsafe to store?
Filtered water has no disinfectant residual left, so it should be refrigerated and used promptly rather than left standing in a warm jug for days.