How To Test for Chlorine in Water?

Chlorine is a popular disinfectant that’s dosed in water to kill harmful pathogens like bacteria and viruses. Homeowners do not typically monitor their water supplies as closely but it is still crucial to identify if you and your family have access to healthy, purified water.

If you get water from your city source, you probably assume that you’re getting good quality potable water since the water gets treated by your local authority.

However, chlorine that’s added in to the water during treatment is not actually removed as it serves to ensure the water is safe even on its journey to your tap. While chlorination protects us from exposure to harmful drinking water contaminants, the chemical itself also has a few harmful human health effects.

What is Chlorine?

Chlorine is a naturally occurring element found in gaseous form at room temperature and it is highly reactive. The strong oxidizing agent naturally deactivates microorganisms by breaking through their cell membrane.

Chlorine is commonly added to drinking water systems to combat diseases such as cholera. Since then, chlorine has been widely adopted as a disinfectant across different applications.

Why Is There Chlorine in Drinking Water?

As mentioned above, chlorine acts as a disinfectant when added in small amounts. The excellent disinfecting agent oxidizes natural substances to deactivate microorganisms.

In fact, the transition to chlorination as a disinfection process has been linked to an immense shift in public health by treating harmful pathogens like bacteria, viruses, protozoa, and other microorganisms that can cause us to get sick after consumption.

Chlorinated water usually contains low levels of free chlorine and is generally considered safe for consumption. However, there are some who would prefer not to consume any of such chemical for two main reasons: the water tastes unpleasant and it is known to lead to some health effects.

While there are other means of disinfection like RO and UV purification, chlorine is relatively cheap and readily available, which is why it is often selected as the main disinfecting route by public water systems to keep their cost down.

Why Is It Important to Test My Water for Chlorine?

If your water source is from the municipal, then it is recommended for you to conduct residual chlorine testing in your drinking water. All municipal water supplies use either chlorine or chloramine to disinfect their water, hence it is best to run a few tests to identify chlorine levels and if there are any other toxic disinfection byproducts in your water.

How To Test for Chlorine in Water

If you are getting your water from the municipal and are wondering how to test chlorine in water, then you’ve come to the right place. This section will discuss the several chlorine testing steps you can take to check your chlorine concentration level.

Test Kits

The market has several chlorine test kits that can be used for testing chlorine levels and it depends on the type of chlorine you want to test for. There are kits for testing free chlorine, total chlorine, residual chlorine, etc.

Pool Test Kits

A pool test kit uses a liquid chemical known as Orthotolidine that will change to yellow color if there’s presence of total chlorine. To use a pool test kit to check for chlorine, just fill a tub with water and add 2-3 drops of the chemical and check if there’s any color change.

However, do note that this method doesn’t check for free chlorine, only the presence of total chlorine in your drinking water.

Color Test Kits

A color test kit uses a tablet chemical known as DPD that will change color to pink when there’s presence of chlorine. Color test kits are very simple to use and much less expensive compared to digital meters. And if used properly, the color test can give accurate results too.

Chlorine Test Strips

Chlorine test strips are another popular method to measure free chlorine levels in drinking water. This test can be used to measure chlorine including total and free chlorine in your home’s water supply.

To use the chlorine test strips, just take a piece of test strip from your kit and dip it into a sample of tap water (some may instruct you to hold it under running tap water, so be sure to read the instructions before using).

The test strip will change color after a few minutes, remove it from the water and compare the test strip’s color to a color chart that’s included in your test kit. The chart will help you determine how much chlorine is in your drinking water.

Digital Colorimeters

If you’re looking for a more accurate chlorine testing method to measure how much chlorine is in drinking water, then you should consider getting a digital colorimeter. Digital colorimeters come in two different methods: DPD tablets and an insertion vial method.

The first one uses a DPD tablet that’s added to sample water. This will cause the color to pin, indicating the presence of chlorine in drinking water. The second method involves inserting a vial into the meter that will read the intensity of color change by emitting wavelengths.

Digital colorimeters give fast and highly accurate readings. This makes them a piece of suitable equipment for those who do not want to wait too long to know how much chlorine in drinking water.

Certified Laboratory Testing

Test strips and other at-home testing methods may not always produce precise results that you want. If that’s the case, you can always opt to send your sample water to a certified laboratory to get your chlorinated water quality tested.

Certified laboratory testing not only can tell you exactly what type of chlorine is present in your water (combined chlorine, free chlorine or total chlorine), but it can also tell you what other contaminants you have in your tap water.

This option gives you detailed and accurate results of your water quality but one drawback to this is that you’ll need to send your water sample to the laboratory and wait several days for the results.

Is it Important to Remove Chlorine in Drinking Water?

Whether you want to remove chemical compounds from your water or not depends on personal preferences. Low levels of free chlorine in water is not harmful to health but there are certainly risks if present in high levels.

The Environmental Protection Agency (EPA) have released a statement saying that low concentrations of chlorine of up to 4 milligrams per liter (mg/L) or ppm is safe for human consumption with harmful effects unlikely to occur. However, some do not want to take the risk and prefer to have combined chlorine totally removed from their water.

Water with too much chlorine will result in chlorine vapors, which gets commonly released during showers. Chlorine vapors are known to lead to several health effects including nausea, cough, vomiting, and even loss of consciousness.

Besides that, having too much chlorine in your water can also lead to skin and eye irritation as it can dry out your skin and hair. However, this issue is usually more common in swimming pools since swimming pool water is treated with higher levels of chlorine compared to drinking water.

In addition to potential health effects, chlorine in drinking water can taste unpleasant. So if you notice an off chemical taste in your water, you’re likely to be dealing with chlorine issue.

Can I Remove Chlorine from Water?

Yes, certainly there are different ways that can help you remove free chlorine and total chlorine from your drinking water. Below we will touch on several methods you can use if you’re facing with too much chlorine in your water.

Activated and Catalytic Carbon Filters

One of the most affordable methods for reducing chlorine levels in municipal water is to use activated or catalytic carbon filters. Since free chlorine molecules are bigger than the filter’s micron size, the activated carbon filter will trap chlorine and other contaminants on their surface, allowing only pure water to pass through to your tap.

Catalytic carbon filters have an even larger surface area which will make them even more capable of eliminating chlorine and combined chlorine from water. Carbon filters can be used in whole-home water treatment systems, as well as smaller countertop filters, pitcher filters, and water bottle filters.

Reverse Osmosis

Carbon filters can help to reduce chlorine levels but if you need something to completely remove residual chlorine and free chlorine, then you should consider reverse osmosis treatment. This system forces the water through multiple filtrations stages at high pressure and can effectively remove up to 99.9% of total dissolved solids (TDS).

The main feature of the reverse osmosis system is a semi-permeable membrane with tiny pores that block even the smallest contaminant from passing through. This results in pure water that’s free of chlorine and other harmful contaminants. Reverse osmosis systems can be installed underneath a kitchen sink but there are also whole-home options that are far more expensive.

Ultra Violet Light

Another way to remove chlorine from water is to use ultraviolet light technology that will disperse wavelengths between 200 to 600 nm. This method can remove up to 15ppm of chlorine and chloramine molecules. This is a feature that not many people are aware of as they thought UV light can only be used to kill pathogens.


Chlorine is a volatile compound that can be easily removed via a simple evaporation technique. In fact, chlorine evaporates on its own without boiling the water. Just leave a water pitcher overnight and the chlorine should evaporate on its own by morning.

This is the cheapest method that won’t cost you much but is also the most time consuming since you will need to wait for the compounds to evaporate from the water.

Boiling Water

Boiling your water can significantly reduce the time it takes for the chlorine to evaporate from your water. Just add water to your kettle and boil it. However, take note that boiling your water removes chlorine and not chloramine.

Chemical Purification

Chloramine does not offer favorable conditions for pathogens to grow but chloride atoms are stable and can promote the growth of microorganisms. Using products that offset chloramine in water samples can react and produce chloride. One method you can take is to neutralize or remove chloramine with Cambden tablets.

While the tablet can help remove chlorine compounds, they do increase the number of total dissolved solids in your water. An alternative is ascorbic acid which will not increase the TDS.

Water Filter

Water filters are excellent at removing or reducing the unappealing taste and odor of chlorine water. However, instead of going with a fluoride water filter, get one with charcoal as it’s known to be able to remove chlorine ions in chloramine molecules. The filter can also be linked up with an RO system to handle ammonia products in water.

It’s recommended for you to get a whole house water filter that can be installed at the point of entry to your home instead of a countertop or under sink filter. This will ensure that your entire house benefits from clean, filtered water that’s free of chlorine. However, if you have a tight budget, you can consider using an undersink water filter instead to help offset chloramine.


We have come to the end of our article on different tests for chlorine levels as well as the different methods for removing chlorine. Regardless of whether you prefer to use specialized water treatment facilities or to rely on a more natural solution, there’s no doubt about the many benefits of drinking chlorine free water.

Frequently Asked Questions

Do I need to test my water for chlorine if I have a private well?

No, you do not need to test your water quality for chlorine contamination as free chlorine is a chemical that’s added to public water for disinfection purposes.

Unless you add chlorine into your well, it is unlikely that chlorine will end up in your local groundwater. However, your water may still be at risk of other chemical contamination from pesticides and herbicides, especially if you live in an agricultural area.

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