About
Do you know what's in YOUR water? Learn about water quality, water quality testing, and water quality testing products that can help you make informed, educated decisions regarding the water treatment options for your home, office, swimming pool... and life.
Contact Us
Got a question about water quality? Want to share a water quality article or water quality article with others?

Visit our Contact Us Page to ask a water quality question or submit water quality information.

RSS Feed
Get the most recent water quality posts and comments by subscribing to the Water Testing Blog RSS Feeds.
Subscribe to RSS! Subscribe to RSS Comments!

Archive for the ‘Free Chlorine’ Category

Jan
31

Liquid Reagent Turns Yellow in Presence of Chlorine

Water Testing BlogChlorine, Chlorine Testing, Combined Chlorine, DPD, Free Chlorine, Home Water Test Kits, Home Water Testing, Testing Devices, Total Chlorine, Water Test Kit, Water Testing

Today’s inquiry came to us from ‘Kishore’ who asked a question about a liquid test reagent that turned yellow when added to a sample of water containing chlorine-based water disinfection tablets.

Dear Sir, I mixed chlorine tablets(water purification Tablets) in water. my friend taken water in Test tube. mixed one drop of liquid then water color changed in yellow. what is name of that liquid. how to by that.please can sent details.

Hello, Kishore, and thank you for the inquiry about a liquid test reagent that turns yellow in the presence of chlorine. Based upon your description we suspect your friend used a chemical called ‘OTO’ to perform the testing. OTO stands for Orthotolidine dihydrochloride. It test for total chlorine (free chlorine plus combined chlorine collectively).

Pool test kit for total chlorine and pH
Pool Test Kit for Total Chlorine & pH
Using OTO and Phenol Red

You can find OTO in most pool supply stores, as it normally comes in the more basic pool water testing kits for total chlorine and pH, the two most commonly tested pool water quality parameters.

Many companies also sell the two reagents separately since they do tend to ‘go bad’ after a year once opened and exposed to air.

If you want to perform more precise chlorine concentration testing for free chlorine, the compound most people have the most interest in (usually) when attempting to determine if water has had the proper amount of disinfectant added to it, you will want to invest in a drinking water test kit that uses DPD-based reagents. ( What is DPD? )

For an even simpler means of testing the chlorine levels in water samples you may want to consider a product such as the SenSafe Free Chlorine Water Check, an EPA Approved method for determining free chlorine concentrations in drinking water, or the WaterWorks 2 Free & Total Chlorine product that uses the same free chlorine testing method as the SenSafe Free Chlorine Water Check and also includes a separate test area for total chlorine.

Want to know more about the differences between free and total chlorine? Check out an article called Free Chlorine, Combined Chlorine, Total Chlorine.

One more thing about OTO before we go: We have heard that some countries have outlawed its use due to scientists having evidence that it may cause cancer in humans… so check local laws before making a purchase!

We hope this helps!

Sep
16

Popular Water Testing Topics

Water Testing BlogChlorine, Chlorine Testing, Combined Chlorine, DPD, Fluoride, Fracking, Free Chlorine, Hardness, Home Water Test Kits, Home Water Testing, sensafe, Testing Devices, Total Chlorine, Water Quality Testing, Water Test Kit, Water Testing, watersafe

Every so often we receive questions from readers who ask something along the lines of, “What do most people ask about?”

Seemed odd at first (several years ago), but after getting asked the same thing so many times we eventually came to the conclusion that a good number of people really and truly don’t know what questions they ought to have about the quality of their drinking water.

Therefore, for your reading pleasure we will now give a list of the 10 most popular topics on Water Testing Blog for the month of August (2011):

  1. Free Chlorine, Total Chlorine and Combined Chlorine
     
  2. Testing for Fluoride in Water
     
  3. Converting Hardness: Grains per Gallon to Parts per Million
     
  4. What is DPD?
     
  5. Chlorine Testing: Drinking Water vs. Pool Water
     
  6. Simple Chlorine Testing Meter
     
  7. Dirty Pool Water Can Make You Very Sick
     
  8. Testing for Chlorine in Drinking Water
     
  9. Lead in Soil
     
  10. Private Well Water and Natural Gas Drilling

In no way does the above list begin to scratch the surface of what curious folks read on our site, but it may help you decide what questions YOU want answered… and if you come up with a question or topic you’d like us to address, send it to us using our submit a comment/question form.

It did, however, kind of shock us that hydraulic fracturing (aka: fracking), a means of extracting natural gas from shale buried deep beneath the Earth’s surface, came in so low on the list given the amount of (bad) publicity hydraulic fracturing has received in the past few years.

We also found it somewhat odd that bacteria in water did not make a single appearance in the list but then again, most folks in the United States have city/municipal water and make the assumption that city/municipal water couldn’t ever contain something as common as bacteria — and that, friends, can sometimes become a dangerous assumption to make!

Science Project Water Test Kit 10-Pack
Science Project
Water Testing Kit

Free & Total Chlorine Test Kit
Free and Total Chlorine
in Water Test Kit

Nitrates and Nitrites in Water Test Kit
Nitrates and Nitrites
in Water Test Kit

Pesticides in Water Test Kit
Pesticides in Water
Test Kit (Atrazine/Simazine)

Heavy Metals in Water Test Kit
Heavy Metals
in Water Test Kit

Bacteria in Water Test Kit
Coliform Bacteria
in Water Test Kit

Jul
25

Free Chlorine Levels in Irrigation Water

Water Testing BlogChlorine, Chlorine Testing, Free Chlorine, Total Chlorine, Water Quality Testing, Water Test Kit, Water Testing

Today’s question comes from ‘Mohamed’ who asked, “How much should be the free chlorine in the irrigation water? We are treating sewage water and sending it to farm lands. What is the international standard of the irrigation water in respect to free chlorine?”

WaterWorks 2 Free & Total Chlorine Test Kit
WaterWorks 2 Free & Total Chlorine Test Kit

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.

Filter Water: eXact Chlorine Photometer
eXact Chlorine Photometer

Filter Water: EPA Approved Free Chlorine Test Strip
EPA Approved Free Chlorine Test

Pool Center: Taylor Fas - Dpd Titration
Taylor Fas – Dpd Titration

Jul
22

Filter to Remove Chloramines

Water Testing BlogChloramines, Chlorine, Chlorine Testing, Combined Chlorine, Free Chlorine, Personal Water Filter, replacement water filter, Sanitizer, Total Chlorine, Water Filter

Do not let a clever sales pitch or catchy marketing jingle fool you. Many common drinking water filter systems do NOTHING to remove or reduce chloramines in water. They simply lack the technology in their filtration media to do so.

Chloramine Removal Filter

We mentioned this filter (the Pentek ChlorPlus) in the past and now feel the need to mention it again since we continue to receive inquiries from people asking why their water filters fail to remove all of the chlorine smell from their water.

The majority of water filters readily available in the marketplace do NOT remove chloramines, also known as combined chlorine. Most carbon filters remove free chlorine only. It takes a specialized type of filter like the Pentek ChlorPlus to cleanse water of unwanted chloramines.

Does my water contain chloramines?

Whether your municipal water system uses free chlorine or chloramines as its primary sanitizing agent we cannot say, but in either case your water will certainly contain chloramines. Unsure why? Take a look at this brief tutorial on free chlorine, total chlorine and combined chlorine.

That’s just a cartridge… What sort of housing does it go in?

A very keen observation followed by a very good question! The Pentek ChlorPlus filter for chloramine removal fits in most standard sized 10″ (by 2.5″) filter housings including, but not limited to, models manufactured by companies like Pentek, Ametek, US Filter, Bruner, American Plumber, Cuno, Filterite, Keystone, Water Resources and most Harmsco filter housings.

As always before purchasing a replacement cartridge for your water filter system, check, double check and TRIPLE check to make sure your housing will accommodate the filter cartridge you wish to buy!

Jul
16

Monkey Business at the Wastewater Treatment Plant?

Water Testing BlogCity Water Test, Free Chlorine, Home Water Testing, Municipal Water Test, sensafe, Total Chlorine, Water Quality Testing, Water Testing, watersafe

While we do like to hear that the legal system has taken an interest in prosecuting those who threaten the safety and potability of water supplies, public or private, through acts of negligence or on purpose, it still bothers us that people would actually do things on purpose that could put the water supply of others at risk.

Free & Total Chlorine Test Strips
Single Dip Method Free & Total Chlorine
Test Strips w/ 0 to 5ppm Detection Range

Today we stumbled across an article from a Chicago area paper talking about how a Federal Judge must decide whether or not a water company and also two of its employees should face charges for allegedly raising free chlorine levels intentionally right before taking readings and then allowing them to drop to potentially unsafe levels at other times throughout the day.

In the spirit of allowing both sides to present their case, we will post the entire article… which left us with more than one nagging question.

A federal judge has delayed ruling on whether to dismiss criminal charges claiming United Water Services tampered with water testing at the Gary Sanitary District.

Attorneys for United Water argued during a hearing Tuesday morning at the U.S. District Court in Hammond that the government’s indictment doesn’t actually cite any illegal activity.

The company, as well as two of its former employees, Gregory Ciaccio and Dwain Bowie, are charged with raising chlorine levels just before daily samples were taken for tests then lowering it again after the samples were taken to amounts not strong enough to properly kill off E. coli bacteria.

United Water operated the GSD from 1998 until last year.

However, Steven Solow, attorney for United Water, argued during the hearing on a motion to dismiss that the GSD’s wastewater permit allowed for the company to raise and lower chlorine levels. “Those are not improper things to do,” Solow argued.

He added that United Water would increase the chlorine levels in the morning, which is when the samples were taken, because people use more water in the morning and that every waste water treatment plant in the world changes its chlorine levels throughout the day.

However, David Mucha, an attorney with the U.S. Environmental Protection Agency, argued that United Water’s actions did violate its permit. The daily samples are supposed to represent what the water is like at the plant during that day, not just at that instant in time, Mucha said.

“This case is very simple,” Mucha said. “They altered normal operations at the time of sampling.”

If the sample doesn’t represent all the water at the plant on the day of the sample, then it’s useless, he said.

He also dismissed Solow’s argument that raising and lowering the chlorine levels weren’t illegal. Mucha said that done on their own, each was fine but that they became illegal when coupled with being done right before and after tests were taken. He likened it to how people can legally drink and can legally drive but can’t legally drive drunk.

Further, Mucha said, the government has to prove only that a person knowingly tampered with water samples for a conviction. U.S. law does not require any other provision.

U.S. District Judge Rudy Lozano recessed the hearing to look at the permit and filings. Mary Hatton, spokeswoman for the U.S. Attorneys office, said that a ruling likely wouldn’t come until after Aug. 1 because of deadlines for a filing by the defense. ( source )

Our first question…

… deals with the frequency of testing: “Why did the plant only need to test in the mornings?”

Our second questions deals with the real results of the raising chlorine levels (supposedly) to pass inspection and then lowering them to potentially unsafe levels: “Did anyone get sick or suffer any form of harm as a result of these actions?”

Don’t get us wrong based upon that second question. We just want to know more about how these folks got caught. If someone got sick as a result of what the water company did, then this case would have ended in a guilty verdict without the need for the judge to deliberate longer… right?

Bitter truth about public water systems?

While few people would argue that the United States of America, when examined as a whole, has one of the most technologically advanced network of public water distribution systems in the world. This does not, however, mean that all of the systems do all of the testing they should at all the right times.

The article above, as well as articles we’ve read over the years about public officials and private firms fabricating water test results in an effort to save money, makes us leery of our great system… yet grateful as heck that for the most part our greatest fears about our public water supply deal mostly with ‘minor’ breaches in protocol rather than instances of blatant disregard for the maintaining of sanitary practices in our water treatment facilities.

Testing for chlorine in drinking water at home?

Do average people have the ability to keep tabs on the amount of chlorine in their drinking water? Absolutely! Companies like WaterSafe and SenSafe make reliable, accurate and completely affordable test kits for detecting levels of both free and total chlorine in tap/drinking water.

WaterSafe All in One Water Test Kit
All in One Water Test Kit

WaterSafe: Chlorine and Hardness Test Kit
Chlorine and Hardness Test Kit

WaterSafe: Well Water Test Kit
Well Water Test Kit

Jul
1

Chlorine Testing Meter for Swimming Pool?

Water Testing BlogChlorine, Chlorine Testing, DPD, DPD Tablets, Free Chlorine, Pool Water, Testing Devices, Total Chlorine, Water Quality Testing, Water Test Meters, Water Testing

As we expected, the number of questions we received recently about swimming pool water has definitely increased. Today’s inquiry comes from a Water Testing Blog reader who hails from Pakistan and he/she asked:

Dear Sir/Madam,
hope you will be fine.i need some information regarding digital chlorine tester for swimming pool water .i read about extech cl200 testing metre.kindly send me the literature and price for it .
thanks
an early response is appreciable
farhan

Now before any of you go and criticize this person’s grammatical skills when typing in English, think more about the person’s commitment to keeping a proper chlorine level in swimming pool and the time it took to submit a question to this site.

ExTech CL200
ExTech CL200 Total Chlorine
Testing Meter for Water

ExTech CL203 ExStik Total Chlorine Test Reagent Tablets
ExTech CL203 Total Chlorine
Test Reagent Tablets

WE commend ‘Farhan’ for his/her efforts and for transcending the language barrier to ask a question about proper chlorine testing in pool water.

On the topic of the “Extech 1200C” for chlorine testing in pool water, we took a look at the ExTech web site and did not find a meter in the chlorine/fluoride in water detection called the ‘Extech 1200C’… so we found ourselves a bit puzzled by your question.

We DID, however, see the ExTech CL200 Chlorine Testing Meter which uses Extech (CL203) Exstik ExTab™ Chlorine Reagent Tablets, a undoubtedly a proprietary blend of DPD-1 & DPD-3 reagents, to test for ONLY total chlorine concentrations in water.

The obvious problem we see with this meter for pool water testing, despite its USEPA credentials for total chlorine testing (in waste water), deal with the meter’s INability to test for free chlorine concentrations in water.

Proper Pool Water Testing Requires Free AND Total Chlorine Testing!

That heading said it all. Proper pool water care requires both free AND total chlorine testing.

Why? Quite simply, it does little good for the sanitation of a pool to have an in-range total chlorine reading with a very low, or non-existent, free chlorine reading. When that happens the pool contains mostly, if not entirely, chloramines (aka: combined/used chlorine molecules) which possess very little (limited) oxidizing power… and limited oxidizing power means limited sanitizing capabilities.

Improperly sanitized pool water can EASILY become a home in which various bacteria, parasites and viral ‘issues’ which will flourish, breed and infect swimmers if left unchecked.

Repeated Moral of the Story

Invest in a meter that test for both total chlorine concentrations AND free chlorine concentrations.

We suggest using a meter like the eXact Micro 7+ Pool & Spa Meter because it tests for not only free AND total chlorine, but also for Total Alkalinity, Bromine, Calcium Hardness, Copper, Ozone, Permanganate, and pH… all with the same meter!

Earlier we talked about the Extech’s USEPA credentials so naturally we figure you want to know if the eXact Micro 7+ Meter has credentials, too — and it does! When used with DPD chemistry (and the appropriate procedures, of course) the meter qualifies as an EPA Compliant device for testing free an total chlorine in drinking water.

“But Wait! There’s More!” Screamed the Announcer

As an added bonus, the eXact Micro 7+ Pool Meter also has the ability to test for Ammonia, Chloride/Salt, Chlorine Dioxide, Chromium Hexavalent, Cyanuric Acid, Iodine, Iron, Low Range Total Hardness, Manganese, Nitrate, Nitrite, Acid pH, Alkali pH, Potassium, Sulfate, Sulfide, and Turbidity — when operated in ‘% Transmission’ mode with the appropriate eXact Micro 7+ Reagent Strips.

Filter Water: eXact Micro 7+ Pool Testing Meter
eXact Micro 7+ Pool Testing Meter

Filter Water: eXact Micro 7+ ReagentStrips
eXact Micro 7+ ReagentStrips

Jun
14

Question: Why is My Lawn Yellow?

Water Testing BlogChlorine, Chlorine Testing, Free Chlorine, Home Water Testing, Total Chlorine, Water Quality Testing

Today’s question comes from a woman in Illinois named ‘Gretchen246′ who asked a very interesting question… about her lawn.

“Why is my lawn green? A healthy lawn is the sign of a healthy home and my lawn is yellow. Allthe lawns here are yellow and we all fertilize and feed and do all we’resupposed to but the lawns are still yellow. Could it be the water?”

Sad to say, but the little kid in us wants to say, ” Gretchen, your neighborhood needs a leash law to keep wandering dogs from peeing all over your lawns!” Ha ha. Yep. The kid in us has not, yet, grown up all the way… and we hope it never does! :)

On a more serious note, if every lawn in your neighborhood has the same issue (bad grass), then it stands to reason that all of your lawns have at least SOMEthing in common. Typically all yards in a development will share a similar soil type (i.e. composition, pH, etc.), environmental conditions (rainfall, amount of sunlight, etc.) and quality of water used to keep them hydrated.

Since we know very little about soil we will pass on the opportunity to discuss that topic and move in for the kill on a topic we DO know something about: Water. Since you say your lawns stay yellow, a sure sign of a dead or dying lawn, perhaps your lawns don’t particularly care for something in the water?

As our first guess, we cast our vote for chlorine. Most municipal water systems use a form of chlorine to keep biological contaminants from growing in the water and water lines. Once out of the water line, however, chlorine will continue to wage war on biological organism… like the grass in your lawn.

Chlorine in my water?

How do you know if your tap water contains chlorine? Perform a simple test for chlorine using a product such as the WaterWorks 2 Free & Total Chlorine Test Strip. We like this product because it provides reliable test results for both free and total chlorine concentrations in water at the same time and in just a few minutes.

There’s chlorine in my water… Now what?

Well if the chlorine poses a problem (i.e. it kills your grass!) then we heartily suggest removing it from the water you use on your lawn. The products below from Gar’n'Gro should have the ability to help with that task.


Gard’n'Gro Chlorine Removal Filter


Pre-Filter for Gard’n'Gro Filter


Replacement Gard’n'Gro Chlorine Filter


Replacement Gard’n'Gro Pre-Filter

For those interesting removing chlorine from their drinking water, you may want to consider installing a simple, yet effective, faucet filter such as the Crystal Quest W2 in your kitchen.

Jun
13

What Does Cyanuric Acid Do in Pool Water?

Water Testing BlogChlorine, Free Chlorine, Pool Water

Although not often (these days) that we get many questions pertaining to pool water, this one question does tend to get asked at least five or six times a year: “What does cyanuric acid do for pool water?”

Calcium Hypochlorite Powdered Chlorine
Calcium-Based Chlorine Powders & Tablets
Require the Use of Stabilizer Stabilizer

Honestly, cyanuric acid does more for the chlorine in your pool water than it does the pool water itself. As an element in water chlorine LOVES to more or less run wild and leave the water first chance it gets if not controlled (stabilized) by a compound like cyanuric acid.

In the absence of a chlorine stabilizing compound things like sunlight, wind and just plain chlorine’s tendency to ‘off gas’ would make it extremely difficult to maintain a free chlorine residual in pool water. Without a free chlorine residual pool water can easily turn green with algae, become cloudy and most CERTAINLY become a breeding ground for water dwelling bacteria and other pathogens.

Two forms of cyanuric acid?

Back in the day you could only get cyanuric acid as granules that you had to mix in a pail to form a slurry and pour down the skimmer (slowly!) with the pool pump running.

Now, however, you can purchase cyanuric acid as a concentrated liquid… which we can ASSURE you saves a lot of time!

Anyone who has ever had to mix, swirl, pour, mix, swirl, pour, mix, swirl, pour, etc., etc., etc., over and over again for a large pool will know EXACTLY what we mean by that last statement. Pouring too much of the cyanuric acid granules into the skimmer too quickly could result in dangerously high levels of pressure in the filter.

In the Swim: Cyanuric Acid Granules
Cyanuric Acid Granules

In the Swim: Cyanuric Acid Liquid
Cyanuric Acid Pre-Mixed Liquid

May
20

Electronic Pool Testing Meter

Water Testing Blogalkalinity, Chlorine, Chlorine Testing, Copper, DPD, eXact Micro 7+ Meter, Free Chlorine, Hardness, pH, Pool Water, Testing Devices, Total Chlorine, Water Quality Testing, Water Test Kit, Water Test Meters, Water Testing

As usual the warmer weather (in most of the US) has brought out the folks who have questions about pool water and how best to take care of it. Today’s question comes from ‘ActionLassie007′ who asked,

eXact Micro 7+ Pool Testing Meter
eXact Micro 7+
Pool Testing Meter

“Do they make meters for pool testing that regular people can afford? Last yr our poolguy had a meter and I asked him how much it cost. He told me one thousand and some change. He lie to me so I would not go get one and he loses a customer?”

Wow. Interesting situation, right? Personally we’d have fired the guy for telling an outlandish lie. Yeah, sure, SOME equipment used to test pool water MAY cost upwards of a thousand dollars or more, but would the average pool maintenance person REALLY spend that kind of money? We doubt it.

We suggest, Lassie, that you take a look at the eXact Micro 7+ Pool Water Testing Meter… which costs well under a thousand dollars, by the way. :P


2009 Pool & Spa News Readers' Choice Award
Pool & Spa News
Readers’ Choice Award Winner

Combining the reliability and repeatability of a photometer w/ the dependability of proven chemistry methods such as DPD (for chlorine testing) and phenol red (for pH testing), the eXact Micro 7+ Pool Testing Meter puts the power of accurate water testing into the hands of the people who need it most: pool owners.

A definite advantage offered by this particular pool meter: Versatility. The pool testing meter tests for 7 critical pool water parameters directly and with the use of a conversion chart and correct reagentstrip it can test for a number of other water parameters, as well.

What comes in pool water test kit?

In the basic kit you will find everything you need to test for free chlorine, total chlorine, pH, calcium hardness, total alkalinity, dissolved copper, and cyanuric acid.

May
12

Filter to Remove Chloramines

Water Testing BlogArsenic in Wood, Arsenic Test, Bottled Water, Chloramines, Chlorine, Chlorine Testing, Coliform, Combined Chlorine, Copper, Disinfectant, Disinfection Byproducts, Fluoride, Free Chlorine, Testing Devices, Total Chlorine, Water Filter, Water Quality Testing, Water Testing

Not a fan of chloramines in your drinking water? You now have a means of removing those pesky chloramines!

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 Resurces, 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.

Filter Water: Free & Total Chlorine Testing
Free & Total Chlorine Test

Filter Water: DPD-1 for Free Chlorine Testing
DPD-1: Free Chlorine Testing

Filter Water: Chlorine Testing Meter
Chlorine Testing Meter