‘TomToo’ very recently — as in a few minutes ago — asked about chlorine testing and which chlorine test he should use:

“Saw your chlorine sale announcement and have a question. The water in our beach house stinks really bad of chlorine when we first get there and we want to test to make sure it’s safe to use but you have free and total chlorine strips. How do you know which to use?”

Thanks for your inquiry, TomToo, and believe us when we say others share your confusion when it comes to knowing which type of chlorine they need to test for.

Lucky for you, though, we have simple answer if your concern deals only with worrying about having too much chlorine in the water. You should test for total chlorine.

The USEPA set the Maximum Contaminant Level for chlorine in drinking water at 4 ppm (parts per million) and that number takes into account ALL of the chlorine in a water sample, meaning both free and combined chlorine.

Moral of the story?

If you need to know the FULL amount of chlorine in a drinking water sample, testing for total chlorine makes the most sense.

We do not know of an International Standard for free chlorine levels in irrigation water but we do know that most States in the US require wastewater treatment plants to neutralize TOTAL chlorine levels before discharging water into the environment and that wastewater treatment facilities must test for total chlorine residuals in their effluent streams on a regular basis to make sure the chlorine concentrations stay virtually non-existent.

Why worry about chlorine in the environment?

If allowed to enter the environment chlorine can and will effectively kill or damage biological organisms that it comes in contact with. In great enough concentrations chlorine will wipe out all plant life in a body of water as well as any animals or fish in the water.

We use chlorine to render safe (i.e. KILL) biological contaminants in our drinking water and if released into a natural habitat the chlorine will render safe (i.e. KILL) any and all plant an animal life until it loses its effectiveness.

Testing for free & total chlorine?

Whether you prefer test strips, wet chemistry kits or a water testing meter… you have plenty of choices when it comes to testing for both free and total chlorine levels in drinking and treated waste water.

Chloramines? What are chloramines? Take a look at this earlier Water Testing Blog entry on Free Chlorine, Combined Chlorine and Total Chlorine and get a quick education on the topic!

Whether created as a byproduct of disinfection via free chlorine or the intended disinfectant in a water system, most people do NOT like the taste and odor of chloramines in their water.

Thankfully Pentek has come out with a product called the Pentek ChlorPlus 10 Chloramine Removal Water Filter Cartridge that fits in standard 10″ (x 2.5″) filter housings used in filter sytems produced by companies such as Pentek (obviously!), US Filter (recently acquired by Pentek!), Cuno, Filterite, Keystone, US Water, Water Resources, Harmsco, and many other popular brands of water filtration systems. If your system uses a standard 10″ x 2.5″ housing, the Pentek ChlorPlus 10 ought to fit just fine!

Having said that last bit, please check the dimensions of your current filter and/or housing before ordering this product!

Looking for a 10″ replacement filter with NSF Certification? The Pentek ChlorPlus 10 uses a component tested certified to NSF Standard 42.

What does the Pentek ChlorPlus 10 remove/reduce? Using 1 micron carbon block technology this product (255416-43) should seriously reduce chloramine concentrations in drinking water and in doing so remove the (offensive) taste and odor associated with chlorine while also helping to pull out unwanted sediment, if present.

Today’s ‘question’ hits a lot of those same points in a new, and somewhat confusing manner. It comes from TamTom18894: “Our shower water contains a lot of chlorine and we think it too high. Yes?”

Not sure how TamTom thinks we will figure out the answer to their question since we have no interest in going to their home and testing their shower water… so we will, instead, discuss simple ways to test chlorine levels in tap water so they can figure out the answer on their own… and then list a few ways to reduce the levels of chlorine that they find.

First, test the water for chlorine residual. The simplest method we know of requires very little time and tests for both free and total chlorine at the same time. The WaterWorks 2 Free & Total Chlorine Test Kit provides fast, dependable results for both free and total chlorine concentrations in water within a minute.

For those who prefer a more ‘traditional’ method, such as a wet kit that uses DPD as its reagent, you probably either already have a kit you can use or you know where you can get one… but did you know an easier method of getting the DPD into your 10 mL sample exists?

If not, then you really ought to check out the DPD-1 ReagentStrip Delivery System which adds a precise dose of DPD-1 to a 10 mL sample without the need for crushing tablets, working with hard-to-open powder pillows or counting drops of messy liquids.

For more precise results, some people turn to meters such as the eXact Chlorine Photometer which can test both free and total chlorine concentrations from 0 to 11 ppm w/ no tablets to crush, drops to count, or powders to mix.

Once you know how much chlorine you have in your water, and what variety of chlorine you have in your water, you can then set about the task of selecting a water filtration device that will best address your individual water quality needs.

Removing free chlorine from shower water

The easiest way involves adding an inline shower filter such as the Sprite High Output Shower Filter which you place behind your existing shower head. It removes: 98.9% of free chlorine, rust from water, sulfur smell, and bad odors. Additionally, it reduces iron oxide, chlorine vapors, and scale build-up on shower surfaces.

Don’t already have a shower head? Need an excuse to get rid of your existing shower head? You can get the same NSF / ANSI 177 Certified shower filter pre-fitted with a good looking, 2.5 GPM shower head. The Sprite High Output Shower Filter (-A) comes in three finishes (brushed nickel, chrome and polished brass).

Removing combined chlorine (chloramines) from shower water

Many devices will claim to remove combined chlorine, total chlorine and/or chloramines. We want you know that in our experience (thus far) we have yet to come across a shower filter that will perform that task. Inline shower filers simply do not have the required amount of filtration media required to do a good job removing chloramines from shower water.

Chloramines have a high amount of chemical stability and as such require special consideration when attempting to remove them. Typically a device capable of effectively reducing chloramines (combined chlorine) levels in drinking water will have a relatively large media bed of Granular Activated Carbon (GAC) and/or a specialized ion-exchange resin.

Larger media beds mean more time in contact with the filtration media intended to remove the chloramines.

We have rumors of ‘catalytic granular activated carbon’ (cGAC) but have not, as of yet, learned enough about it to discuss its merits and/or shortcomings.

What does .25/.25, and .5/1, in the free/total column from the Taylor Test Kit represent in a pool log, are these levels safe for swimming. If not what levels from the Taylor Test Kit would be normal. What ORP level is considered to dangerous for swimming. I’m sorry I forgot to mention this is an indoor public pool.

For legal reasons we cannot tell you that your pool water definitely meets all the necessary criteria for getting labeled as ‘safe’, but we cannot assist you with interpreting the data in the log book.

First, we suggest you take a look at an earlier blog posting we did called Free Chlorine, Combined Chlorine, Total Chlorine. The information in that posting will help you to understand the differences between the three basic ‘types’ of chlorine. You will also find some very useful information on Pool Water Testing Blog’s entry entitled Free Chlorine and Combined Chlorine — in a Swimming Pool.

Getting back to your question about the readings in the log book, the entry of “.25 ppm free chlorine & .25 ppm total chlorine” indicates that all of the chlorine in the pool has got converted into chloramines (combined chlorine) and you had no free chlorine, your pool’s main sanitizing agent, available to ‘kill’ any unwanted biological contaminants in the water.

The second entry, “.5 ppm free chlorine & 1.0 ppm total chlorine”, indicates that you had 0.5 ppm free chlorine available in the pool to wipe out any unwanted biological contaminants… and for the record, most pool experts agree that water in a swimming pool ought to contain between 1.0 ppm and 3.0 ppm free chlorine — assuming the pool does not use an alternative sanitizer system (i.e. Baquacil).

By the same token, most pool experts also agree that swimming pool water ought to contain as few chloramines (combined chlorine) as possible. Elevated chloramine levels can contribute to added eye irritation and foul tastes and smells in the water.

What do ORP levels mean?

We freely admit that we do not know a whole lot about ORP and that many people have different ideas as to its usefulness as a means of judging a body of water’s relative safety, but we do know that many water experts believe a properly pH balanced pool (readings between 7.2 and 7.6) with an ORP reading greater than 700 means that the hypochlorous acid (free chlorine) will work effectively as a sanitizing agent.

Michael said he has an indoor pool?

In the case of indoor pools, you will DEFINITELY want to keep combined chlorine counts to minimum because the fumes can build up to noxious levels very quickly. Indoor pools tend to have warmer water temperatures (which increase chlorine off gassing) and less air movement across their surfaces.

Michael said it’s a public pool?

Consult with your local health department and find out what THEY want to see in terms of pool water chemistry because in the end, when they stop by to perform an inspection, their word, and ONLY their word, will determine whether or not your pool stays open that day.

My wife and I just bought a home and although the real estate agent showed us all sorts of confusing paperwork that supposedly proved our tap water passed all sorts of tests we still have our doubts. We want to do some testing ourselves. What are the most commonly tested water parameters? Thank you.

We will answer that question in two ways: 1) We will ask a water testing and filtration dealership; 2) We will look at this site’s history and see what pages people have loaded most often this month.

IsoPure Water replied to our inquiry by listing the top three selling water test strips: SenSafe Free Chlorine, WaterWorks Total Hardness and SenSafe Total Chlorine.

With regard to the most popular postings on Water Testing Blog, in the month of January 2010 more people looked at these blog entries than any others:

• Hardness: Grains per Gallon vs. Parts per Million
• Testing Chlorine Levels: Drinking Water vs. Pool Water
• Your Baby Needs Safe, Clean Drinking Water
• Free Chlorine, Combined Chlorine and Total Chlorine
• Acceptable TDS Meter Readings Do Not Guarantee Safe Drinking Water

“Drinking or even showering in tap water can double the risk of having deformed children,” says study.

Drinking tap water while pregnant may double the risk of serious heart or brain defects in the unborn child, research suggests.

A study of almost 400,000 babies found a clear link between chemicals formed during chlorination and the occurrence of a trio of birth defects.

Drinking water, showers, swimming pools and even the steam from a boiling kettle can all contain the problem chemicals called trihalomethanes, or THMs, the researchers said.

While the study was carried out in Taiwan, it is thought up to one in six British homes is exposed to levels even higher than those found to cause concern, with concentrations tending to be particularly high in the spring and autumn.

The researchers stressed it would be impractical for pregnant women to avoid tap water and said the onus was instead on the use of disinfection methods which limit levels of the chemicals.

The Birmingham University study compared details of birth defects with the level of THMs in tap water.

The analysis of almost 400,000 babies showed those born into regions where levels were around 80 per cent more likely to have a hole-in-the-heart defect and more than 50 per cent more likely to have a cleft palate.

Their odds of suffering anencephalus – a condition that causes much of the brain, skull and scalp to be missing – were almost doubled, the journal Environmental Health reports.

While birth defects are rare – occurring in about 2 per cent of births – the three flagged up in the study are among the most common.

It is thought the chemicals may harm the unborn baby directly. Alternatively they may damage the woman’s eggs. Although the study did not prove that the chemicals caused the birth defects, it is not the first to make the link.

Researcher Professor Jouni Jaakkola said: ‘Our findings don’t just add to the evidence that water chlorination may cause birth defects, but suggest that exposure to chlorination byproducts may be responsible for some specific and common defects.

THMs are the products of a chemical reaction between chlorine and organic compounds common in lakes, rivers and reservoirs.

The amount of THMs made during chlorination vary according to where the water comes from and the disinfection process, meaning highly chlorinated water does not necessarily have the highest levels.

Home water filters may not be entirely effective at removing the chemicals and bottled water may also be tainted.

Professor Jaakkola said the solution was for water companies to use disinfection procedures that keep the production of THMs to a minimum.

He said: ‘Water disinfection has an important purpose in reducing microbial load and reducing acute gastro-intestinal infections.

‘Some have claimed it is the best public health measure ever introduced.

‘We are talking about rare health effects and a modest risk increase.

‘I don’t suggest stopping using tap water but we have to be conscious that at population level some risks may be related to increased levels.’

The Drinking Water Inspectorate, which is tasked by the Government to monitor the safety of tap water, said its own, larger-scale research had failed to find a link between THMs and birth defects.

Principal inspector Sue Pennison said: ‘Obviously we will review this research, engage our health expert colleagues, and look to see if it means we need to do anything more. But there’s no reason for people to be worried.

‘Chlorination is reliable and has been used for centuries. The only reason diseases like cholera and typhoid are not in our water supply is because of chlorination.’

The water industry trade body, Water UK, said it would consider the findings but chlorination in the UK meets World Health Organisation guidelines. ( source )

Testing for Disinfection Byproducts?

There are no ‘simple’ ways to test for disinfectionm byproducts (DBP’s), but homeowners can find out if the water supplied by their public water systems possibly contains disinfection byproducts by using a test kit like the WaterWorks^TM Free and Total Chlorine Test Kit. See below:

WaterWorks^TM 2 Free and Total Chlorine

The test strips above have two pads: 1 for measuring Free Chlorine Residual and 1 for measuring Total Chlorine Residual.

• No Color on Either Pad: This typically means the water contains no chlorine at all. If on a residential water system, a person may want to re-test and/or consult your local water authority. Please note, though, that the absence of free and total chlorine does NOT necessarily mean the water does not contain disinfection byproducts. A possibility exists that all of the chlorine (or chloramines) added at the water treatment plant have left the water before getting to where it was drawn for testing.
• Color on Both Pads: This means both free and total chlorine exist in the sample water and a possibility exists that the water also contains disinfection byproducts.
• Color on Free Chlorine Pad Only: This should not ever happen because the total chlorine concentration represents the sum of the free chlorine plus the combined chlorine in the water. You cannot have free chlorine registering w/o it also registering as part the total chlorine concentration.
• Color on Total Chlorine Pad Only: If the public water system uses a chlorine/ammonia based disinfectant system then the water will more than likely NOT contain disinfection byproducts. If, however, the public water system uses a free chlorine residual as its disinfectant, then a good chance exists that the water contains disinfection byproducts.

Don’t forget that you can always find out definitively whether or not your tap water contains disinfection byproducts by simply calling your local water company and asking questions. As a general rule, the law requires them to divulge that sort of information upon request to anyone who asks.

Ideally for the farmer, the water going into the ground and/or getting sprayed over his fields should contain as low a disinfectant concentration as possible since chlorine kills more than just microorganisms. In too great a concentration it destroys plant life as well.

How Can Farmers Monitor Chlorine Levels?

While several methods for testing chlorine levels in farm water exist, and all have merit, the simplest chlorine level testing method for farmers comes in the form of dip-n-read test strips. They require no formal training, cost very little, and give fast, accurate results typically in under a minute. See below for examples of test strips well suited for testing chlorine levels in farm water:

Do Farmers Test for Free Chlorine or Total Chlorine in Farm Water?

Most farmers test for total chlorine in farm/irrigation water. The total chlorine concentration includes the free chlorine residual and the combined chlorine (chloramine) residual. Both free chlorine and combined chlorine can function as oxidizers, though free chlorine typically does work much more effectively.

SenSafe Total Chlorine Test Strips (0ppm to 10ppm)

• Example 1: Before water from a well can pass a coliform bacteria test at a certified laboratory and get approved for human consumption it must test as having absolutely no chlorine residual in it.

• Example 2: Federal, State and Local Environmental Laws/Regulations prohibit the discharging of highly chlorinated water from a wastewater treatment facility or from any other water processing facility. Chlorine, even in low concentrations, poses a serious danger to the ecosystem and the releasing of too large an amount into environment can wipe out the area’s vegetation and animal life very rapidly.

What Type of Chlorine Should One Test For?

Typically speaking, when concerned about the amount of chlorine residual in the discharge from any sort of wastewater treatment facility, most people check for total chlorine. Testing solely for free chlorine would not suffice for environmental purposes because combined chlorine, also called chloramines, can still have harmful effects on the environment despite not having the as great an oxidation potential as free chlorine.

How Can One Test for Low Levels of Total Chlorine?

Test Strips: Quick, easy and cost effective. Test strip methods for chlorine concentration determination offer extreme amounts of convenience and require little or no technical training. Just dip the strip and compare the color of the test area to a color chart. (total chlorine, ultra low total chlorine)

DPD: Typically used in conjunction with a colorimeter, DPD methods for chlorine concentration determination give more precise results than most visual methods, but as stated, they typically require the use of instrumentation (see eXact Micro 7+). For environmental compliance monitoring and reporting purposes, most government bodies require the use of an EPA Compliant DPD testing method.

Titrations: A time consuming method which typically uses DPD in liquid form and requires a certain amount of laboratory skills. Not very practical for field work. Uses liquid reagents which have a shorter shelf-life than comparable powders, tablets, etc.

Determining the Chlorination System Your Water Supplier Uses

Chlorine Smell Test: In general, water containing only chloramines gives off a much more objectionable odor than water containing a free chlorine residual. While true that a free chlorine system generates chloramines as the free chlorine gets used up fighting whatever biological contaminants it encounters, the amount of odor given off by those chloramines will typically not surpass the amount of odor given off by water treated solely with chloramines.

Home Water Testing: While no test strip exists to check JUST the chloramine concentration in water, one does exist to check both the Free Chlorine Residual and the Total Chlorine Residual: The WaterWorks^tm 2 Free & Total Chlorine Strip accurately measures both parameters with a single water quality test strip.

WaterWorks^tm 2 Free and Total Chlorine Home Water Test Kit

• If the free chlorine test area shows color AND the total chlorine test area shows color, then your water supplier most likely uses free chlorine as its primary disinfectant.

• If the free chlorine test area does not show color BUT the total chlorine test area does not show color, then your water supplier most likely uses chloramines as its primary disinfectant.

Although the above testing method will yield quality results, calling your local water supplier will get you the same information.

Should you wish to test for the presence of just free chlorine or just total chlorine in drinking water, the following simple test strips will yield fast, accurate and reliable results in under a minute:

• Total Chlorine Test Strip (480010)
• Free Chlorine Test Strip (481026)