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).

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, including our own online store, also sell OTO & Phenol Red 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 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!

I need to purchase a quick test means to locate water leaks in supply pipes to my residential water service meter. The county water uses a small tear able foil packet of chemicals that turns red when mixed with chlorinated water. My home has very low water pressure and volume, we are serviced by an extremely old and much damaged 2″ pvc line serviced by the Logan County PSD, Logan WV. The PSD does not have the time or personnel to investigate all of the water puddles located in the community where I live. I would like to be able to quickly and safely test any ground water in the hope of finding where the line rupture is.

Thank you, Michael, for this inquiry. From the sounds of things your local water department uses DPD powder pillows or tablets to investigate the nature of puddles suspected to have formed as a result of leaks in municipal water lines. The chemical DPD turns various shades of pink through dark red in the presence of oxidizers such as chlorine, bromine, ozone, etc.

Where can the average citizen get DPD?

Chemical supply houses often carry DPD powder and/or tablets in bulk and many swimming pool stores tend to carry DPD powder pillows and tablets intended to work with swimming pool test kits.

For what you want to do, though, we suggest you look more closely at DPD powder. Specifically we think you should focus your acquisition efforts on DPD-4, a compound which will detect both free chlorine and combined chlorine in a water sample. This matters because once water treated with free chlorine exits a controlled environment (i.e. leaves the pipe through a crack, fissure, etc.) the free chlorine will immediately begin acting on any and everything in its environment… and that will result in only combined chlorine possibly reaching the surface and creating a pool of water.

Problems with testing puddles for chlorine?

While not totally impossible that a pool of chlorinated water could potentially wind up on the surface over or near a leak from a chlorinated municipal water line, we believe that only a good sized leak could produce water in the volume required to get water containing highly reactive chlorine molecules through contaminant filled soil and up to the surface — with readable/detectable chlorine residual levels high enough to detect visually (or with a portable meter) using DPD.

But, since your local water department does it, either your water line infrastructure routinely has large leaks or its water lines lie very close to the surface. Either way, a swimming pool supply company called In the Swim carries DPD-1 tablets and DPD-3 tablets.

Crushing (carefully) and then mixing them (carefully) in equal parts should enable you to create your own version of DPD-4, but to play it safe we suggest using the appropriate amount of DPD-1 in a 10 mL sample of water and then using the DPD-3 in that same sample — per the ‘accepted’ procedures for free and total chlorine concentration determination.

“Do your DPD Chlorine tabs work in Hach equipment?”

Good afternoon, Ronda, and thank you for this inquiry. When weighing the different DPD options (tablets, powders, reagentstrips, etc.) make sure you note the sample size that each test method will work in. As a general rule most devices that use DPD as a reagent will have 10 mL sample sizes, but we have also seen devices that use 15 mL sample sizes, 7 mL sample sizes and 20 mL sample sizes.

Check your machine’s manual to find out what sample size it takes. In order to remain compliant with whatever drinking water directives you follow you will need to match up the sample size w/ the correct reagent amount.

Specifically, though, you asked about the DPD tablets for chlorine testing that we have shown on our site and as far as we know all of the DPD products we have shown on our site work for 10 mL samples — except for the eXact Micro DPD products which work in smaller samples.

Two 10-mL Tablets/Strips/Powders for a 20-mL Sample?

While in theory that would work, definitely check your approved testing method to see if it expressly forbids that sort of thing and/or if it specifically calls for a brand or type of chlorine reagent delivery method. In the past we have seen where testing protocols have gotten so granular that they call out not only the type of DPD used, but also the brand of the test meter and DPD used for chlorine testing.

(100) DPD #1 Tablets (1,000) DPD #1 Tablets

(100) DPD #3 Tablets (1,000) DPD #3 Tablets

]]> http://watertestingblog.com/2011/11/10/do-the-dpd-tablets-work-in-hach-meters/feed/ 0 http://watertestingblog.com/2011/04/22/inexpensive-free-chlorine-meter/ http://watertestingblog.com/2011/04/22/inexpensive-free-chlorine-meter/#respond Fri, 22 Apr 2011 13:03:49 +0000 http://watertestingblog.com/?p=3628 No matter how many ‘new’ and/or ‘innovative’ methods scientists devise to make water safe for drinking, we believe a certain faction in society will still put its trust in the sanitizing effects of free chlorine. This also means we believe a need for chlorine testing will always exist.

As an immediate example of this need, a Water Testing Blog reader named John recently asked, “Hi I am installing a 5000 litre water tank which i intend to add chlorine to and need an inexpensive free chlorine meter could you advise me on what to purchase as this is a new venture for me. Regards,John M.”

Thank you, John, for your question and more importantly for reminding us that we needed to examine the cost of chlorine meters at some of our favorite online merchants: FiltersFast.Com and FilterWater.Com.

In no particular order…

• FiltersFast.Com still carries the eXact Micro 7+ Water Testing Meter and they currently sell the basic water quality kit for $200.

  While perusing the site we noticed that FiltersFast.Com appears to carry several of the more commonly used replacement reagentstrip bottles for the eXact Micro 7+ meter: Total Alkalinity, Bromine, Calcium Hardness, Free Chlorine, Total Chlorine, Copper, Ozone, Permanganate, pH.

  eXact Micro 7+ pH Test 486639

  eXact Micro 7+ Copper Test 486632

  eXact Micro 7+ Free Chlorine 486637

  eXact Micro 7+ Total Chlorine 486670

  eXact Micro 7+ Total Alkalinity 486641

  eXact Micro 7+ Calcium Hardness 486629

  We saw no other chlorine testing meters available on the site.

• FilterWater.Com continues to carry the eXact line of water testing meters and currently has three kit versions of the eXact Micro 7+ available: Standard Water Quality for $249, Pool and Spa for $249 and Chlorine Photometer for $229.

  Each kit features the same meter, but comes with a different set of reagentstrip bottles tailored to meet the needs of a specific water testing application/market.

  In addition to the eXact Micro 7+ meter kits, we also noticed that FilterWater.Com also carries a newer eXact meter called the eXact Micro 8 Meter. That meter did not, however, appear to test for chlorine.

And in conclusion…

The USEPA approves of using DPD when testing drinking water and/or wastewater for chlorine content. Therefore, we suggest you invest in a system that uses DPD for free chlorine and/or total chlorine residual testing.

EPA Compliant Meter for Free & Total Chlorine Testing
. . . When Used w/ Reliable, Trusted DPD Chemistry

As a general rule, if your water has a chlorine smell to it, then you most likely have, at the very least, chloramines (combined chlorine) present. This does not, however, rule out the possibility that your water also may contain a free chlorine residual, too.

For the record, health officials and scientists agree that chlorine gas does NOT do the body any favors and in too great a quantity can cause lung and eye irritation… so we suggest not performing the ‘sniff test’ if you can help it.

Taste test: Not all water that contains chlorine will smell like a swimming pool. While combined chlorine (chloramines) has a strong odor associated with it, free chlorine does not. Therefore water that may not stink like chlorine may still possess a strong chlorine taste.

We do NOT advocate the taste test method for any reason. We mentioned it just so that we could talk about why water can lack a strong chlorine smell and yet still have a strong chlorine taste.

Chemical test kit: We know of many different test kits that the general public can use to determine the free and/or total chlorine concentrations in their drinking water.

“Wait… Did you just talk about two different types of chlorine?”

Yes, because as we discussed during a few moments ago, one can have free chlorine and/or combined chlorine in their water. Typically free chlorine acts as the main sanitizing and/or disinfecting agent in a chlorinated water supply and once the free chlorine finds an organic contaminant to ‘kill’, it becomes entangled with the contaminant and forms a combined chlorine molecule.

Therefore, it stands to reason that a chlorinated water supply may contain both free and combined chlorine at the same time if the free chlorine molecules have successfully neutralized all biological contaminants and the effort did not require the use/exhaustion of all free chlorine molecules present in the water supply.

Getting back to chemical test kits, please…

Now that we have established the existence of different types of chlorine which may or may not exist in a water supply, we will now discuss different ways of testing for chlorine in a water supply.

• Test Strips — Perfect for field testing because they require the user only to dip the strip into the water and compare the color of the test pad/area to a color chart that came with the package of test strips. Products exist for the detection of both free and total chlorine. People can even get a single test strip to test for both at the same using a product called WaterWorks 2
• ‘Wet’ Chemical Test Kits — Considered by most as the traditional, tried and true method for testing the quality of water. Most ‘wet’ kits typically require dissolving DPD as a tablet, powder or liquid into water samples and either comparing the colors of resultant solutions to color charts or adding drops of an additional chemical until a second color change reaction occurs.

  Simpler ‘wet chemistry’ test kits for chlorine (i.e. 2-way pool water test kits) use a different chemical called OTO (Orthotolidine) and detect total chlorine (free chlorine + combined chlorine = total chlorine).

  Problem w/ using OTO: No way exists to use OTO in a way that will allow a person to determine the free chlorine concentration.

  The DPD reagent system does, however, allow for differentiation between the two if a water sample has DPD-1 added first, gets analyzed, and then has DPD-3 added… and then get analyzed again.

• Water Testing Meters — Most water testing meters for chlorine (i.e. the eXact Chlorine Photometer) require the use of DPD, a chemical indicator which turns a shade of pink/red in the presence of chlorine molecules. DPD-1 indicates the presence of free chlorine and a combination of DPD-1 plus DPD-3 indicates the presence of free and/or combined chlorine (total chlorine).

So… Which method of chlorine testing will work best for you? Ask yourself the following questions:

1) Do you need to test for free chlorine, total chlorine or both?

2) How much accuracy and precision will you need in your results?

3) If performing testing for reporting purposes, what do the rules and regulations governing your profession say you must use as a testing methods?

Once you have answered those three questions you will have a clear idea of whether you should use chlorine test strips, wet chemistry test kits for chlorine testing or chlorine testing meters to determine chlorine concentrations in your water.

I need to buy Dpd Tablets and I have not found a supplier nor a Manufacturer to buy from.

Kindly Link me with Dpd Tablets Manufacturers who can supply me.

We thank you very much, Janet, for your inquiry and suggest you take a look at the material below, as it will lead you to what you seek:

For those of you interested in learning more about DPD and its uses, please refer to an earlier posting entitled What id DPD?.

National Stock Number (NSN) for “Chlorine Test Tablet” — 6550012191061 and 6550014257957

SONORA – The State Water Resources Control Board says in a proposed order that the Central Valley Regional Water Quality Control Board disregarded excessive chlorine being discharged into Woods Creek from a Sonora sewage treatment plant and also inappropriately increased the amount of chlorine that Sonora and Jamestown government agencies were allowed to discharge into the creek.

The proposed order the state board issued this week would require the regional board to revise its pollution permit for the treatment plant that serves the two cities to bring chlorine discharges within legal limits.

Woods Creek flows into Don Pedro Reservoir, a popular fishing area and a tributary to the Tuolumne River. The order points out that even extremely low concentrations of chlorine are damaging to fish populations. ( source )

Government regulations restrict the amount of chlorine (both free AND total) that a company or water treatment facility may pump back onto the environment because even in low concentrations, chlorine has the ability to inflict serious harm on an ecosystem.

Testing for Chlorine:

• Liquid Test Kits: Companies such as Taylor, Lamotte and others manufactures test kits which make of use liquid reagents.
• Test Strips: Many companies manufacture test strips which measure chlorine levels as low as 0.05 ppm (see SenSafe Free Chlorine & Total Chlorine) and as high as 5,000 ppm (see Water Check Ultra High II Free Chlorine).

• Chlorine Meters: For people with color blindness or simply the desire NOT to have to interpret color changes on the pads of test strips or in liquid samples, chlorine testing meters take all the guesswork out of testing free & total chlorine levels in water samples. Almost all chlorine testing meters use DPD Reagents in the form of liquids, tablets, powders or reagentstrips.

Per the request of several men and women currently serving in the United States Armed Forces and other branches of the Unites States Government, we will begin posting possible alternate products for popular (established) NSN’s (National Stock Numbers) related to water quality testing.

NSN: 6550012191061, 6550014257957 — Chlorine Test Tablets

“DPD REAGENT TEST TABLETS FOR CHLORINE ANALYSIS. PACKAGED IN INCREMENTS OF 100. LAMOTTE.”

Alternatives:

• DPD 1, 3 and 4 ReagentStrips — Faster and more convenient than traditional DPD test tablets. No MSDS required. Safe to use on production room floors of food processing facilities. EPA Compliant testing method. Packaged in bottles of 50 or individually wrapped in foil packs. Costs as low as 8 cents a test.

eXact^® Strip DPD ReagentStrips

Note: We have found that the products suggested above meet or exceed the specifications of the original NSN (National Stock Number) item. This does not mean, though, that you may substitute them in place of the item on a Government Contract. We provided the above information as possible sources of water quality testing products for consideration in future Contracts/Bids only.