Pool Water Testing

	The WaterLink SPIN Lab, pictured above, is the state of the art, in-store Professional Water Analyzer.  Pool or Spa owners can use a variety of reliable testers or test strips, as well as the electronic ColorQ or PockeTester models. Click any image for Product and Ordering Information.

How to properly test pool water? Proper pool water management starts with the analysis of the pool water. Tests such as pH and chlorine need to be performed by the pool owner, on a frequent or daily basis, depending upon the usage conditions. The Chlorine test should be performed by a method that tests for Free Chlorine, as it is the most important form. Tests such as chlorine stabilizer,  total alkalinity and calcium hardness are performed occasionally during the season and can be performed by a pool owner or dealer. Tests for heavy metals such as iron, manganese or copper should be performed at the beginning of the season or at the first indications of pool water discoloration or a pool surface staining problem. These pool water tests are usually performed by local dealers. Tests for nitrates, phosphates or Total Dissolved Solids (TDS) are performed by some dealers, on a occasional basis, if a more obvious explanation is lacking. Maintaining or balancing proper pool water chemistry or pool water balancing is important to help to minimize problems, assure optimum water quality and to maximize the ownership experience. Water testing has never been simpler: the new ColorQ digital, water analyzers eliminate all color-matching and guesswork. If problems arise, refer to the Pool Problems Page, as a source of problem-solving information, broken down into various categories. Scroll down the page and click on the linked keywords, catch phrases or images, in the archived answers below, to access additional information, on that topic or product.

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► Test Strip Reader Or A Digital ColorQ?

Hi Alan. You have an excellent website and I appreciate the willingness to answer questions.  So here goes. I am a new Hot Tub/Spa owner. I have been testing with test strips that require me to evaluate the colors.  I have strips that measure Chlorine, Bromine, pH, Alkalinity and Hardness. I have trusted the results.  Lately with all of the reading I have done I have become very fearful of my pH being out of range and thus I purchased an automatic test strip reader.  This reader has strips that measure Chlorine/Bromine as well as pH and Alkalinity. The strips are dipped and placed face down on the reader and the reader determines the values. The problem is that I can not get the old method and this new reader to agree ever.  I have no idea what my pH level is because one reads 7.2 and the standard strips measure 6.0. The strips and the strip reader are made by the same company, so there is no compatibility issue.  I realize that I could be judging the colors incorrectly, but I don't think that I am. Which one should I trust? I have checked your website Test Equipment Store, for the ColorQ testers, and I am wondering, if I should be returning my automatic reader and purchasing one of these.  My reader cost about $70 but I don't mind spending more if it will read more accurately. I also found that there seems many types of ColorQ models. Which one I should be considering. Thanks.

Dave W., 7/13/2012

Test strips are reasonably accurate, but were never intended to be a precision test method. Some people have difficulty picking up on subtle color differences. Using a test strip reader sounds like a good idea and for some people, it might be. However, from a chemist's point of view, it is adding another layer of complexity and cannot add to the accuracy of the test results. Your own experience bears this out. I have no way of telling you which answers might be more reliable and you should not have to guess. If you can return the tester, I certainly would do so. The ColorQ family of digital water analyzers are a much better choice. There is no color-matching or guesswork involved. You get a digital readout, with the answers for as many different test factors, as that model can perform. The ColorQ testers are simple-to-use and, yet, use the same technology as the most sophisticated pool water testing labs. I think it sets the standard, for the industry, with a selection of models that will suit every pool or spa owner. For your purposes the #2056 ColorQ PRO 7 would be the best choice. You may not need the cyanuric acid test, but all the others are needed, for best water management. Thanks for writing and helping me set the record straight.

Sincerely. Alan Schuster, 7/13/2012


► Test Strip Reliability?

What is the accuracy of swimming pool test strips?  I can't seem to get any of the manufacturers to send me lab data on the accuracy of the strips.

Richard K., California, 4/23/2011

Good question! Test strips are not a precision laboratory means to test pool water. They are intended to provide satisfactory and reasonably accurate test results, with convenience and ease of use.  If the test strip reads a pH of 7.4, that should indicate that the pH is 7.3-7.5. For swimming pool or spa use, this is not a problem and is more than adequate. If the Free Chlorine reads 1.0, that should indicate a concentration close to that value. Does it matter if the true reading is 0.9 PPM or 1.1 PPM? No! It does matter, if the reading is 0.2 or 2.2 PPM. The testing of swimming pool water does not require the precision and accuracy that one would expect of a blood or urine test. Do test strips provide reasonably accurate and useful results? Yes! How you take the water sample or store the test strips can affect the test results. I have a feeling that the manufacturers were reluctant to provide the information because they have no control over how the test is performed, the water is sampled, the directions are followed or how the test strips were stored. However, not all brands are the same in terms of their formulation, manufacture or test chemistry. My own personal experience with the LaMotte Insta-Test product is very favorable. I hope that I have been helpful.

Sincerely. Alan Schuster, 4/23/2011


► High Chlorine Reading?

I just put up a vinyl pool that is 15 ft round x 3 ft high. Since I just filled it I put a packet of Vinyl pool shock (1 lb) with the pool filter running. After a day I did the water test and the OTO level on the tester still shows above 3 ppm and the pH shows above 7.8. I know I can add pH minus to reduce this, but how do I lower the latter to 3 ppm? Thanks.

L. M., Deltona, FL, 6/9/2009

You may not have to anything about the chlorine reading. While OTO is popular, it is far from the most meaningful test. I suggest that you try using LaMotte Insta-Test Strips, as they provide the right kind of information - easily and reliably. This product tests for Free and Total Chlorine and is a much better indication of the pool's sanitizer level. Occasionally, to better assure proper overall pool water chemistry, visit a pool store that has a very reliable, professional lab such as a WaterLink SPIN Lab or Pinpoint system, rather than a less accurate test kit or strip reader.  To locate a dealer near you, go to: LaMotte Professional Testing Center Locator The recommended level for Free Chlorine is 1-3 PPM and the Total Chlorine level should not be more than 1 PPM higher. Using the pool with very high chlorine levels can be irritating. The chlorine level will drop over time as the pool shock reacts with algae and debris. I hope that this information will prove helpful.

Sincerely. Alan Schuster, 6/9/2009


► Professional Pool Water Testing?

I OWN A RENTAL STORE AND JUST GOT STARTED SELLING POOLS, CHEMICALS AND SUPPLIES THIS SPRING. IT HAS BEEN GOING GREAT EXCEPT THAT I AM USING LIQUID REAGENTS TO TEST EVERYONE'S WATER. I DON'T HAVE THE SOPHISTICATED SYSTEM THAT THE ONES IN THE BIG CITY OF KANSAS CITY HAS. MY STORE IS 50 MILES FROM THE CITY AND I'M TRYING TO GET ALL POOL CUSTOMERS, HERE IN RICHMOND AND LOCALLY, TO COME AND LET ME TEST THEIR WATER. SO MY QUESTION IS ARE THE ONES UP IN THE CITY USING A WATER TEST SYSTEM THAT YOU POUR THE POOR WATER IN IT AND YOU GET A PRINTED READ OUT AND WHAT IS IT CALLED? THANK YOU AND LOOK FORWARD TO HEARING FROM YOU.

JULIE R., RICHMOND, MO, 4/18/2008

Not quite as simple as pouring in some water! They are probably using a variety of test equipment, some of which may be fairly automated. The testing results are processed by some type of computer program. If you would like to look into something that is highly automated, does all of the common tests and is simple to operate, I suggest you consider the WaterLink 3 Lab. The LaMotte Water Link Express laboratory virtually eliminates all the measuring and is very fast, as well as accurate. Software is available, for use with this laboratory, to help you draw the appropriate recommendations, from the data that is inputted. And did I mention that you don't have to be a chemist? Confidence in the testing procedure is a two-way street between the dealer and the consumer. In addition, The LaMotte Co. has a locator, on their website, that will direct pool and spa owners to your location.  I hope that you'll find a product that suits the needs of your business and your customers. Good luck.

Sincerely. Alan Schuster, 4/18/2008

Editors Note: The WaterLink Express has been followed by the WaterLink 3, which uses the same UDV technology. The latest breakthrough in water testing is the WaterLink SPIN Lab. It was designed for professional, in-store testing and uses a completely new technology. Absolutely simple to use, it can perform 10 different pool or spa tests and provide a computer printout in only one minute. The era of "just add water" has arrived. 4/26/2012


► Automatic Water Analysis?

I have recently opened a Pool and Spa Chemical Supply Shop near Charlotte, NC and require information and relative costs etc to test our customer's pool water samples as quickly and efficiently as possible. I hope you will be able to assist. Regards.

Brad S,, Concord, NC, 1/21/2012

There are several factors for you to consider as a pool professional dealer. Speed: during peak season, you want to move things along as much as possible. Thoroughness and Accuracy: you need to do all the important tests, when required, with suitable accuracy, from even a relatively new operator. Cost: speed and cost can go hand in hand, to a degree. Simplicity: keeping it uncomplicated by using dosed testing chemicals, disposable components and a minimum items that require rinsing and cleaning for each test. Professionalism: you need to use equipment that will instill confidence in the consumer as well as the water tester. I suggest that you go our Test Equipment Store There you will find information on an extensive line of professional pool water testing equipment, as well as costs and availability. Automated is easily achieved - automatic is more difficult. Your choice will be influenced by budget and needs. You should be able to pick a water testing setup that meets your requirements.  So far as technology and speed are concerned, the new WaterLink SPIN lab is as good as it gets.  Ten different pool water tests and a printout, in only one minute.  Good luck on the venture.

Sincerely. Alan Schuster, 1/21/2012


► Being Better Informed?

I just had to write to say I LOVE your website. It's keeping me sane in my world of three competing pool dealers, with conflicting advice on pool chemistry. Now, if only their measurements would stop conflicting, I'd be home free.

C.P., 9/11/2011

Being better informed helps avoid falling victim to a dealer with the wrong information or test results. Water chemistry is where it starts!  Some new testers are just available. It is the LaMotte ColorQ Water Analyzer. There are 13 different models to choose from: one should be just what you need! It includes everything that is needed. All are simple to use, hand-held, all-digital, accurate and reliable, do all of the important tests, require no color matching or look up charts and are reasonably priced. In the long run, being better informed will save you money, time and should minimize problems.  I'm glad to hear that this website has been helpful, as that is our goal.

Sincerely. Alan Schuster, 9/12/2011


► Trouble Dealing With The Colors?

My son has always tested our pool water, as I have trouble trying to distinguish some of the colors. Is there a simple way to test pool water without having to check colors? Something affordably priced would be perfect. This fall, he will be off to college and I'll be on my own. Thanks for the help that your website provides.

Herb K., Sarasota, FL 2/16/2008

Pool dealers have been using colorimeters to electronically test water for years. The problem is that this type of equipment is relatively expensive and is really only intended for high volume, in-store testing of pool or spa owner's water. A new, reasonably priced product is available that utilizes a hand-held colorimeter. The ColorQ PRO 7 Water Analyzer measures Free and Total Chlorine, Bromine, pH and Alkalinity, Calcium Hardness and Cyanuric Acid. It is done with a colorimeter and all you have to do is read the answers on the large, LCD display. No colors to distinguish and no more guesswork. Perfect for pool owners, pool servicemen, especially, those with color vision impairments. The proper testing of pool water enhances the ownership experience, by helping to assure better water quality and sanitation.  I hope that I have been helpful and that this is a solution.

Sincerely. Alan Schuster, 2/17/2008


► Test Reading Differences?

My pool water is a little cloudy. I tested the chlorine and pH. Chlorine was between 0.1 and 0.4 and the pH was right on. My chlorinator is on full. I added 3 tablets, 3 days ago. I took a sample of water into my local pool store and they found that the free chlorine was 0 and the total chlorine was 0.14. Why would the home test kit show that chlorine was slightly low and the store test found 0? They told me to add some liquid chlorine. Is it possible that the chlorinator is not working properly? Are the chlorine tablets old? They are from last season. Why do I need to use liquid chlorine, when I have a chlorinator? I thought the point of the chlorinator was so you would have to keep adding liquid chlorine. Thanks.

Cindy, 6/6/2004

This is not uncommon, depending upon certain factors. The reason being that the water sample was subject to sampling and storage errors, contamination in the container, storage in a hot car and the passage of time. It is important to use a clean container, sample from below the surface, protect the sample from the effects of heat and sunlight and have it tested on a timely basis. The difference in test reading is well within what one might expect. If the store showed a higher chlorine level, that would be a different matter. Of all the tests, chlorine is the one most affected by these factors. There is probably nothing wrong with the chlorine tablets and they told you to add the liquid chlorine in order to quickly boost the free chlorine level. I hope that I cleared up the mystery. Enjoy the season.

Sincerely. Alan Schuster, 6/7/2004


► TDS And Salt Relationship?

We have a 44241 gallon salt water pool. We own a meter that tells us our salt and total TDS reading.. we have heard that our TDS reading may be a bit higher since it is salt water... did not know if you could give us an equation that would give us a TDS only reading. We have been told that we do not want that number to be above 1500. Some of our swimmers are complaining of rashes and we just want to make sure everything is ok. We do not want to have to drain the pool if it could be avoided. Thank you.

E.M., 4/15/2010

First, you have to understand what TDS Testing comprises.  It is the total of all the salt added to the pool, plus all the chemicals used to balance the pool chemistry and all of the mineral that naturally occur in your source water.  The recommended levels of salt will vary from salt chlorinator manufacturer to manufacturer and even by model. Assuming that the salt level is 3000 PPM and the TDS is 4500 PPM, that means that the TDS would have been around 1500 PPM, even if no salt was added. These values are but a fraction of the levels in ocean water, which can be 15 timers higher than the salt level in your pool. 1500 PPM of non-salt TDS is high and is not ideal, as it can interfere with clarity, water quality and sanitizer effectiveness. You need to test the tap water. In places, like Arizona, it can be 1000 PPM or more, right out of the faucet. In that case, water replacement is not a realistic option. If the TDS is low, partial replacement is an option. Your question refers to bathers getting rashes. The cause of rashes is more likely to be inadequate sanitation, too high a level of combined chlorine, too high a free chlorine level and pH readings that are too far removed from the ideal of 7.2-7.8, as opposed to high TDS. Salt chlorine generators tend to cause the pH to rise, unless regular additions of acid are made. This can lead to a loss of sanitizer effectiveness and increase the possibility of irritation. That is where I would look. See if there is a correlation, between the pH and chlorine levels and the complaints. I hope that this information will be helpful.

Sincerely. Alan Schuster, 4/15/2010


► How Often To Test Pool Water?

I try and test the pH and chlorine at least every other day. Is that often enough? How often should I test for total alkalinity and chlorine stabilizer. Thank you.

Austin H., Augusta, GA, 8/12/2004

Testing the pH and chlorine every other day is quite reasonable. In addition, I would test at the first sign of a change in water quality or during periods of high bather demand. The more important chlorine test is the Free Chlorine Test: free chlorine is the active germicidal form. The total alkalinity should be tested at the start of the season, whenever there are fluctuations in the pH and monthly during the season. The chlorine stabilizer should be tested at the start of the season. Unless the stabilizer level is approaching too high a value, once or twice a season is sufficient. The balancing of the pool water chemistry will, in the long run, solve or avoid many problems. I hope that I have been of assistance. Enjoy the season.

Sincerely. Alan Schuster, 8/12/2003


► Testing For Bacteria?

I live in Boca Raton and I am looking to find a lab to test my pool water for bacteria. Do you know any place to do that? Thank you.

Daphne S., Boca Raton, FL, 11/5/2008

You sound like a new pool owner? It can be done, but testing for bacteria doesn't necessarily tell you much. It is expected that there will be bacteria present in water that people swim in. Even bacteria, such as E. Coli, are not an issue, so long as the numbers are within guidelines. To do that test, you would need to be a bacteriologist, to properly interpret the results and their significance. You are better off putting your efforts into proper sanitation, with some backup. You could use a salt chlorine generator and an ozonator or a Solar-Powered Dual-Ion Mineralizer or combinations to create redundancy and assure proper sanitation. With proper sanitation and filtration, there should be much less reason to be concerned about bacteria. Periodically, give the pool a shock treatment, to help prevent the development of resistant microorganisms. Proper water chemistry is important for both water clarity, corrosion considerations, bather comfort and for the proper action of many sanitizers. The new ColorQ Digital Water Analyzers can provide all the data you need and do it without color matching or guesswork. I hope that this information is helpful.

Sincerely. Alan Schuster, 11/5/2008


► Testing For High Chlorine Levels?

First off, I think your site is great. Next, my question: My pool water is crystal clear but my OTO test for chlorine turned bright orange which I guess means the chlorine level is high. Then I purchased a DPD test kit to test for Free chlorine. The free chlorine tested at 5 PPM. The total chlorine test was not much higher than 5 PPM. Is my free chlorine level too high? Do I need to do something to lower it? There is no odor and my total chlorine level doesn't appear to be too high so I assume my combined chlorine level is not too high. What can I do?

Carlos V., El Paso, Texas, 4/21/2005

It is hard to tell if your chlorine level is too high. OTO and DPD are not very reliable at high levels, because the chlorine affects the test chemicals. When using DPD, you should take the reading, as soon as possible, after adding the test chemical.  Otherwise, you may get a higher reading, as the test can start to register chloramines, if present. A better means of testing higher chlorine levels is with Syringaldazine: a chemical used in some test strips such as the LaMotte Insta-Test Strip product. You might stop adding chlorine and give it a day or so. Otherwise, you could use a chlorine neutralizer product to quickly lower the level. Free chlorine is always the more important test: OTO is not used for this test. I hope that I have been helpful.

Sincerely. Alan Schuster, 4/21/2005


► Bleaching Effect On Test Strips?

I recently had the strong chlorine odor problem followed by a cool weather streak which lead me to leave me pool cover and neglect my normal maintenance for about two weeks. When I opened the cover, I found the pool to be cloudy and green. I used algaecide and shock to resolve this and put chlorine tabs in the dispenser.  It took three days of shocking to clear up the water. The chlorine reading is still so low it is not registering on the test strip. I read that if there is too much chlorine in the water it will have a bleaching effect on the test strip, so I took a sample of the water and diluted it to see if I could obtain a reading. The reading was still low. Should I shock the pool again?

Suzanne B., 9/15/2006

Test strips, such as the LaMotte Insta Test Strips are one of the best ways to measure high levels of chlorine. The bleaching effect, that you are mentioning, is more likely to happen with OTO or DPD testers. I suggest that you add the liquid chlorine or quick dissolving shock, about a pound/gallon per 5,000 gallons, until the free chlorine level is over 5 PPM. Don't drag it out! The longer it takes, the more product will be required. Keep it there until the problem is under control.  You have green water because the sanitizer level was inadequate and algae took hold.  Check the overall water chemistry as well. Make sure that you are testing for FREE CHLORINE. I hope that I have been helpful. If so, please tell your friends about the website.

Sincerely. Alan Schuster, 9/15/2006


► High Chlorine Levels "Bleaching" Test Chemicals?

Sorry to bother you again Alan but just a quick email to see if you can give me some info. I did a pool course a while back and I was reading through the notes and it said if pool chlorine reaches over 10ppm, 'bleach out' could occur. It did not however explain what this meant, nor could I find it on the net. Could you help with this. Many thanks, as always.

Gareth J., UK, 11/18/2009

When the chlorine level get too high, it can destroy the testing chemicals and provide a false result. If you suspect that the chlorine is over 10 PPM, try this. Mix 1 part of pool water with 2 parts of bottled drinking water. Test immediately! Multiply by 3, to get a reasonable approximation of the true reading.  This technique is not valid, with the other tests. For the other tests you would have to use distilled water. pH cannot be done, using anything but the actual water sample, but a few drops of chlorine neutralizer can be added, before testing. I hope this clears up the problem.

Sincerely. Alan Schuster, 11/18/2009


► How Long Do Test Strips Last?

I have some test strips from last year. Are they still good?

Mel. T., Rochester Hills, MI, 5/28/2008

Maybe and maybe not! Most test strips have an expiration date on them. If there is no expiration date on them, don't buy them again! In addition to paying attention to the expiration date, you must make sure that the test strips have been stored away from heat, moisture and light. Always reseal the container immediately after removing a test strip and NEVER REMOVE A TEST STRIP WITH WET FINGERS!  Moisture is the enemy of test strips and can destroy their reliability and reduce their shelf life, regardless of the expiration date. Closing the container can help minimize the moisture problem. Most strips come with a silica gel packet inside and this helps absorb some of the moisture. Even better are the Test Strips packaged with a desiccant liner, as a means of moisture removal. You know how the test strips have been stored, so use this information as a guide. In the future, follow the recommendations, as to handling and storage between uses. If you want to eliminate all the color matching and guesswork, you should consider a ColorQ all-digital water analyzer. Simple to use, with photo-diagrammatic instructions. I hope that I was helpful. Enjoy the summer

Sincerely. Alan Schuster, 5/28/2008


► Saturation Or Langelier Index?

Saturation index for pools? Do you have any, where you can put the pool test results and gives you the answer? Could you let me know? That would be great. Thanks.

Tony, 1/27/2011

There is a page on the website devoted to the calculation of the Langelier or Saturation Index, as well as information on the Ryznar Stability Index. I hope that the information will prove useful.

Sincerely. Alan Schuster, 1/27/2011


► New Pool Owners?

Hi Alan. We recently bought a house with an inground gunite pool. We are having a problem with what I believe is mustard algae. After reading the questions on your website I am confused about free chlorine tests. We bought a test kit to test chlorine levels, but I do not know how to test for free chlorine. Please help!

No Name, 6/13/2007

I suspect that you are using a test kit with a color block for pH and Chlorine. This would be an OTO test kit and it does not measure for Free Chlorine: the active germicidal form of chlorine. I suggest that you try using a test strips. Test Strips such as the LaMotte Insta-Test Strips provide test for Free and Total Chlorine and give you a much better picture of the pool's state of sanitation. The balancing of the pool water chemistry requires periodic testing and helps to minimize water quality problems.  For pool owners that prefer to avoiding having to differentiate slight color differences, the new ColorQ Water Analyzers are just what you need. I hope that I have been helpful. Enjoy the pool.

Sincerely. Alan Schuster, 6/13/2007


► Time To Take Charge?

I have a new pool that was completed six weeks ago. The pool is a 16,000 gallon in-ground gunite pool with an aggregate finish and a salt system in south Florida. I had hired a pool professional to start up my pool and maintain it, since I was told that optimizing a new pool would be difficult. However, after five weeks I noticed that the pool did not register any chlorine level and the pH was always above 8.2. My pool professional indicated that my test strips were not accurate and that the pool was fine. I then proceeded to have a sample analyzed by my local pool supply store and they concurred with my readings. At the time of testing, the chlorine and free chlorine level was 0 ppm, chlorine stabilizer was 0 ppm, total alkalinity was 200, pH was 8.2, TDS was 0 and calcium hardness at 40. They indicated that I needed to get the pH down or risk scaling. Following their instructions, I added chlorine stabilizer, put my chlorine generator on boost mode for 24 hours and have added several gallons of muriatic acid (and fired my pool professional). After 1 week, I have chorine levels around 3 ppm, pH has been ranging between 7.4 and 8.0, total alkalinity at 80.  In order to get the pH level down, I have been adding about a gallon of acid every other day (not sure if adding this level of acid is recommended or not). My problem is my pool finish. The bottom looks good; however, the walls seem to still have a lot of “paste” that has not wore off from daily brushing to expose the aggregate. Additionally, when I run my hand along the walls they seem slimy. The water has always appeared to be clear. Any insights on what’s happening?

Mike T., Florida, 4/6/2007

Your "pool professional" was not very professional. and I have some doubts about the pool dealer. New gunite pools tend to have pH readings on the high side and the use of a salt chlorine generator only adds to the problem. Once the walls cure and the chemistry is optimized, it will level off. Your "pro" did not add stabilizer and that is why your reading is zero. Or is it? The pool store has your TDS at zero and that is impossible. It should be around 3000 PPM, in your case. A calcium hardness of 40 PPM is doubtful, as it is higher right out of your tap. The slimy feeling on the walls is an algal or bacterial slime and is the result of inadequate sanitation and/or circulation. It is time to take charge here and do some testing of your own! I suggest using LaMotte Insta-Test Strips: they are easy to use and provide the right kind of information. There are some "questionable" strips out there, just like there are some questionable " professionals." You need to test for free chlorine and maintain a level of 1-3 PPM. With slime on the walls, boost the level to 5-10 PPM, in order to help destroy these deposits. Your pH should be maintained at 7.2-7.8 and adding acid is how it should be done. A low hardness can contribute to etching, which in turn will drive the pH up. Get the hardness to about 200 PPM. Because you have a salt chlorine generator, I would concentrate on the pH and not worry about the total alkalinity, unless the hardness is over 400 PPM. Make sure the salt level conforms to the manufacturer's recommendations. To help improve circulation you might consider adding The Circulator: circulation boosting device Get the chemistry right and don't rely completely on the action of others. Be better informed. Things will improve.

Sincerely. Alan Schuster, 4/6/2007


► What Levels Of Metals Are A Problem?

We are just finishing up a pool installation and they are getting ready to do the plaster coat. What are the acceptable levels or thresholds for copper, iron and any other materials content in our well water, in order to avoid staining? I want to buy the appropriate test kits from you and would like to know what levels of each would pose a concern for staining.

Joe G., 3/23/2010

Almost any level, that you can measure, can be a problem, with well water. Certainly, 0.1 PPM would be a problem with iron and manganese. If you use a METALTRAP Filter, as the water is being added, you might spare yourself some of the problem. I always suggest use of a metal treatment, when well water is involved. A metals, minerals and contamination removing METALTRAP Dual-Cartridge Filter, with replaceable cartridges, will remove metals and contaminants, before they get into the pool. I hope that this information will prove helpful.

Sincerely. Alan Schuster, 3/23/2010


► Biguanide Testing?

I have used a biguanide test kit with the dropper bottles and test strips. I can't say that I like or feel confident about having to match the colors. Is there any other way to do the testing? Thanks for the help.

Brad M., Naples, FL, 2/6/2008

Good News! The ColorQ Biguanide PRO 5 Water Analyzer is an all-digital, hand-held tester that performs tests for biguanide, pH, total alkalinity, calcium hardness and biguanide shock. There are no colors to match and no look-up charts. It is an ideal tester for anyone with color matching difficulties. And it is affordably priced and easy to use.  Seems to be just what you are looking for. I hope that this information will prove helpful.

Sincerely. Alan Schuster, 2/7/2008


► OTO Chlorine Test?

I have been using an OTO test for years. It almost seemed to be the only test, when we first got a pool. Today, I see more choices. Are they better than OTO? If so, why? Appreciate your advice. Thanks.

Colton T., Austin, TX, 5/12/2009

OTO was probably the first test for chlorine and, in those days, there was a lot less known about the chemistry of chlorine in swimming pools. OTO measures Total Chlorine and that is not as important as Free Chlorine. The newer DPD Test Kits and various types of Test Strips usually test for both Free and Total Chlorine. This gives you a better picture of the sanitizer level and the water quality.  OTO test kits have had their day in the Sun and their use is on the decline. The other kits are better, plain and simple. A ColorQ, all-digital tester would eliminate the color-matching and guesswork and would be an even better choice. I hope that I have been helpful.

Sincerely. Alan Schuster, 5/12/2009


► What's A TDS Test?

My local pool dealer runs a TDS test every now and then. Exactly, what is a TDS test? Thanks.

Josh S., Phoenix, AZ, 10/1/2010

Total Dissolved Solids (TDS) is a measurement of the total concentration of dissolved materials in the water. It is expressed as PPM of sodium chloride (salt). Soft water has a low TDS. Hard water has a higher TDS. Salt water has a very high TDS. High TDS in swimming pools can lead to water quality problems. Most vinyl pools and pools, that are winterized, never encounter a TDS problem. In certain areas of the country, the source water is high in TDS and the pool water may benefit from monitoring. TDS is usually measured with a TDS meter and is relatively easy to perform. Many test meters, such as the one pictured to the right, also test for salt and other factors. Pools utilizing a salt chlorinator should use a meter that tests for salt and not just TDS. It is important to measure the salt content of the water, to assure optimum performance and longer cell life.  I hope that I've explained the TDS test successfully.

Sincerely. Alan Schuster, 10/1/2010


► TDS And Salt Tests?

The subject is TDS. My pool is a residential Fiberglass pool with a salt chlorinator system. I have read so many opposite points of view on TDS testing and on how to test that I am back to two basic questions. Do I even have to test for TDS as part of my routine tests? I have not had a TDS related problem in 3 years of pool ownership in my salt water pool? Some say a TDS problem is caused, 99% of the time by excessive CYA, so you treat the excessive stabilizer problem and ignore TDS. Others state, wait for TDS symptoms to appear and then test for TDS as part of the problem solving process. Others state a TDS problem in a salt water pool is so rare that there is no need to test for TDS. If I should test, what method do I use? Test for conductivity, test for TDS and subtract salt content, test for TDS and subtract initial salt content? Salt test reading is the TDS reading? Thanks for your help (previous and future).

John G., 5/23/2008

Not all TDS readings have the same implications. Years ago, a TDS over 1500 PPM was considered to be terrible. If you live in parts of Arizona, that passes for tap water. Your pool has about 3000 PPM of salt or whatever level the manufacturer of your salt chlorine generator recommends. Some use more salt - others less. Assuming it is 3000 PPM and you get a TDS reading of 4000 PPM. That means there are 1000 PPM of miscellaneous dissolved salts: some naturally present in the tap water and others added to control the pool water chemistry. The list includes bicarbonates, carbonates, sulfates and cyanurates, as the major salts and some lesser amounts of others. Unless you are having clarity or scaling issues, I would not be concerned about testing the TDS. If the cyanuric acid is over 100 PPM, you should replace water. There is no way it accounts for 99% of the difference between the TDS and salt readings. A normal pool has hundreds of PPM of calcium hardness and total alkalinity. Both test as TDS. If you use sodium bisulfate to lower the pH, the water will contain large amounts of sulfates. And this doesn't consider what occurs naturally. I suggest that you use a meter to test for salt. Some of the better testers do test for salt and TDS. Proper salt level is important. Too little and not enough chlorine will be produced. Too much could shorten the life of the salt cell. Tracer PockeTesters are the easy way to test the salt and TDS levels. I hope that I have shed some light on the subject.

Sincerely. Alan Schuster, 5/23/2008


► What Contributes To Rising TDS?

Does sodium bicarb raise TDS levels with fresh water? I have gone from 320 TDS fresh water to 1300 TDS two months later. Thanks.

Dave, 2/16/2007

Everything that dissolves in the water can contribute to the TDS: sodium bicarbonate, sodium carbonate, muriatic acid, sodium bisulfate, cyanuric acid, chlorine, shock, metal treatments, etc. It all gets measured as PPM of sodium chloride, in spite of being a varied mixture of salts. One pound of dissolved salts will raise the TDS by about 12 PPM, in 10,000 gallons of water. I hope that this has helped clear things up.

Sincerely. Alan Schuster, 2/16/2006


► When To Replace A Test Kit?

How long can a pool test kit last? Should it be replaced every year? Thank you.

Carolynne D., Alpharetta, GA. 6/2/2006

It really depends upon the type of test kit and how and where it is stored between uses. Those generalized recommendations to replace the test kits every year are well-intentioned. Because so much depends upon the test readings and there is no simple, foolproof means for determining the accuracy of an older test kit, it is better to err on the side of caution and replace the test kit on a yearly basis.  Some common sense must be applied. Test solutions, that do not look right, should be replaced regardless of their age! All test solutions should be resealed after each use and stored away from moisture, heat and light. Test strips usually have an expiration date. However, if you remove the test strips with dripping wet fingers, the moisture may destroy their reliability and/or shorten their shelf life. Make sure that you remove all test strips with dry fingers and that the container is resealed and stored away from moisture, heat and light. Most test strips are packaged in quantities that will last for about a season and, usually, need to be purchased season to season. If you would like a better type of pool water tester, consider the ColorQ Water Analyzers. These Colorimeter based testers are available in more than a dozen models and require no color-matching or guesswork.  I hope that I have been helpful. Enjoy the pool season.

Sincerely. Alan Schuster, 6/2/2006


► Testing For Salt?

My pool has a salt/chlorinator installed. It required that I add salt to the water at the rate of 20 pounds per 1000 gallons of pool water. I have to keep the salt at 2000-2500 PPM. How often should I need to test the salt level? Thank you.

Rick K., Ormand Beach, FL, 3/2/2005

In your part of the country the pools are open all year. Yes, I am aware that only the "snow flakes" use the pool, in the winter, in your area! This means that your water is not replaced or pumped out for winterizing. I suggest that you test the salt level at the start of "your" swimming season. I'm sure that you'll find it acceptable. I suspect that you have a cartridge filter and, therefore, do not backwash.  In your case, the salt level will only drop due to water replacement or due to pump out because of excessive rainfall.  I suggest that, after periods of heavy rainfall, the salt level be tested to determine, if any, the need to add additional salt. In addition, Test the water for salt, if the salt chlorinator is not producing the expected quantity of chlorine. Test Meters are a simple way to monitor the salt level. Low salt levels can cause this to happen. Otherwise, testing the salt level a few times a year should be adequate. The overall pool water chemistry should be maintained, the same as any chlorine pool. I hope that I have been of assistance.

Sincerely. Alan Schuster, 3/2/2005


► Salt Testing vs. TDS Testing?

Alan, excellent website! Learned more in a few minutes on your page than in several weeks of general web surfing. Couple questions for you. We have a chlorine generator and love it. I use salt test strips to keep tabs on the salt level. It doesn't change much over the course of the (short ) swimming season. But, when I re open the pool in the spring, I have to add back a lot of water and, of course, salt. I have been adding the salt and using the test strips. Today I took a water sample in for analysis at a local pool store. My salt reading with the strips was about 2800 PPM. The store did not use test strips, but simply equated TDS to salt level and told me my salt level was actually 3100 PPM. No real crisis here. But is TDS really an accurate read on the salt level? I suspect this really depends on what else is in the water. Comments? Second question. With all water parameters in balance I still seem to have to keep a close eye on pH and keep pulling it down on a weekly basis. It tends to drift up a lot. I have heard this is normal in a "salt water" pool. Why would chlorine from a generator have more effect on pH than chlorine pucks or other forms of pool chlorine? Are there pH reducers in the chlorine products that  reduce the pH rise in "normal" chlorine pools?

Jim C., Canada, 4/28/2005

TDS measurements include the salt content plus naturally occurring minerals, carbonates and bicarbonates, calcium hardness minerals, chlorine stabilizer and other pool chemicals. These can easily add up to a few hundred PPM or more. A salt test reading is always the more meaningful measurement, as it is what the operation of the salt chlorinator depends on. Salt chlorinators tend to cause the pH to rise. The reason is that alkaline materials are released, as the salt is converted into chlorine. By comparison, trichlor tablets are acidic and tend to lower the pH. I hope that I have been helpful. Enjoy the season.

Sincerely. Alan Schuster, 4/28/2005


► Choosing A Salt Testing Meter?

Have an above ground swimming pool with a salt water chlorinator. [Autopilot] What salt water test METER should I consider and why?

Keith, 10/24/2006

Salt content is important! Too little and not enough chlorine is produced. Too much and the life of the cell can be shortened. Your Autopilot unit can be used with up to 6000 PPM of salt without cell damage, but that is more than is recommended by the manufacturer. There are two good choices LaMotte No. 1749 or LaMotte No. 1766. The latter tests for pH, as well, and costs a bit more. Either will serve your needs. I hope that I have been helpful.

Sincerely. Alan Schuster, 10/24/2006


► Action Based On Test Results?

Alan. First of all I would like to commend you on your website and the information posted. The information is thorough and direct. I was informed last year by a pool professional friend of the family during the non summer months all that was needed for the pool was cleaning the filter and adding a bag of shock plus, once a week in addition to brushing the floor and walls. However, I recently noticed some staining in our in ground pool and wanted to get your feedback prior to taking action. The stains appear yellowish-brownish in a pattern formation on the floor and steps area. The stains are very light but noticeable. When I took sample water to the local pool supply store for analysis, the rep told me that due to the levels of the chemicals in the water, that the best thing to do was to empty out the pool and start from scratch. The water test results are as follows based on their tests: Cyanuric Acid: 275, Chlorine: 10+, pH: 7.5, Copper: 0.08, Alkalinity: 200, Calcium: 500, T.D.S.: 1200, Iron: 0. Your advice is greatly appreciated. Best regards,
 
Sergio S., 5/23/2010

If your pool is gunite, which I suspect, draining is an option. I never suggest draining a vinyl pool. because of liner shrinkage and possible structural problems. The reason that water replacement was recommended was because of the high cyanuric acid level. Water replacement is the only means of lowering the level and 275 PPM is grossly high. Very high levels can interfere with the effectiveness of chlorine.  While some of the other test values are high, I cannot be sure of their relationship to the source water. The stains could be the result of iron and other metals, even though the test results are negative. If you drain the pool, have the tap water tested for metals and add a dose or two of phosphate-free Liquid MetalTrap, in any event. If the tap water test is positive, you should use a MetalTrap Filter, to remove the metals, before they get into the pool. The yellow-brown material could be early mustard algae and it will benefit from a water replacement. If, by chance, the pool is vinyl, replace the pool one-two feet at a time. Evaluate you use of stabilized chlorine. If you are using trichlor tablets, do not use dichlor as a shock, inasmuch as it will speed up the rise in the cyanuric acid levels. I hope that the information proves helpful.

Sincerely. Alan Schuster, 5/24/2010


► The Color Is Orange?

When I test my pool water for chlorine level the color I get, after applying the solution to it, is orange. It starts off a mild yellow but w/in 20 seconds turns orange. I had been running my chlorine at twice the normal dosage (5.0 vs. 2.5). Is this orange color because I went heavy on the dosage. Any help is appreciated. Thank you.

Robert D., 5/23/2009

The orange color indicates that the chlorine level is too high to read, with that tester. That type of tester is archaic and you should use one that tests for both free and total chlorine. The label dose is only a guide - you must add enough to maintain a proper level. For free chlorine testing, I suggest using LaMotte Insta-Test strips, as they provide the right kind of information. To better assure proper overall pool water chemistry, visit a pool store that has a very reliable, professional lab such as a WaterLink SPIN Lab, rather than a less accurate test kit or strip reader.  LaMotte Professional Testing Center Locator I suggest that you start by having the water tested for free and total chlorine. The total chlorine reading should not be more than 1 PPM higher than the free chlorine readings. If it is, add some non-chlorine shock.  I hope that this information is helpful.

Sincerely. Alan Schuster, 5/23/2009


► Measuring Combined Chlorine?

I have a test kit that doesn't give very accurate results for combined chloramines testing . Can you give me any help by suggesting a more accurate method of testing for this. Thank you kindly.

Darlene, 11/16/2004

Test kits do not measure combined chlorine, which includes chloramines. To determine the combined chlorine, subtract the free chlorine reading from the total chlorine reading. Not all testers perform both tests. The LaMotte Insta-Test strips are an easy way to get this information. I hope that I have been helpful.

Sincerely. Alan Schuster, 11/16/2004


► Low Stabilizer Reading?

On our test strip it states that the stabilizer is low. Our pH, CHLORINE and ALKALINITY all read fine. Please advise what might need to be done. The water is fresh- 1 week old. Thank you.

Jim M., 4.18.2007

Low levels of chlorine stabilizer will increase the loss of chlorine, due to the Sun's UV rays. You need to add some chlorine stabilizer (cyanuric acid). You did not provide the reading or how big your pool is. In a 10,000 gallon pool, one pound of cyanuric acid will raise the level about 12 PPM. That should help you figure out what needs to be added, based on the test lit recommendations. If you are using stabilized chlorine, this reading will rise over time. When it reaches 150 PPM, you should replace some of the water. Want to avoid future buildup problems? Have you ever considered a salt chlorine generator. No chlorine to buy, store or handle. No buildup of stabilizer! The LaMotte Insta-Test 6 does all of the important tests and would be a better choice, that the 3-test strip that you are using. I hope that this information is helpful.

Sincerely.. Alan Schuster, 4/18/2007


► Can Type Of Lighting Affect Readings?

I find the my pool water test readings, when taken at night, seem quite different. By then the lights are turned on. Is this possible? Thanks.

Ronald L., 7/1/2007

Definitely could be the problem. Test strips and comparator colors can be influenced by lighting: sodium vapor lights are probably the most troublesome, by fluorescent or dim lighting can be a factor. It is best to read under bright natural light, without direct Sun exposure. One way to avoid all of these problems is with the LaMotte ColorQ Water Analyzers. There are several models and one would be right for your pool. I hope that this will help provide more consistency in the testing.

Sincerely. Alan Schuster, 7/2/2007


► Manganese Test Kit?

Hi, Alan, I have a pool service business on the east end of Long Island. There is a manganese problem in some areas of the south shore. Is there a simple test kit that I could use, in the field, to test for manganese. It just might help solve a lot of problems for me. Thanks.

Tommy C. Quogue, NY, 3/19/2011

There are compact and portable field manganese test kits that are suitable for your needs.  Your customers will appreciate all the aggravation that you're are helping them avoid.   If you know manganese is present before the pool is filled, you can use METALTRAP Filter to remove much of the manganese and iron. It should remove it all and can make a huge difference. Thereafter, it should be used to treat all new water, as it is being added. It simply attaches to the garden hose, being used to add the water. I hope that I have been helpful.  One more word of advise.  Add 1 dose of a quality mineral treatment product, such as Liquid METALTRAP, for each 0.5 PPM of manganese found.  This should provide an excess to help deal with other minerals that might, also, be present.  Have a good season.

Sincerely. Alan Schuster, 3/19/2011


► Using A Chlorine Neutralizer?

I have 2 different pH test kits. One recommends neutralizing chlorine prior to measuring pH while the other does not. Obviously this results in very different pH readings. Which method should be used in order to guide pH manipulation. Thanks.

Tony, 11/22/2005

It would have been helpful to know whether you have a pool or spa. Most phenol red solutions, but not necessarily all, have a chlorine neutralizer formulated into the product. This is important in order to help protect the phenol red from being "bleached out" by high levels of chlorine or bromine. Spas are more likely to be using bromine than are pools and the lack of a chlorine neutralizer can result in false high pH readings. You should be able to get comparable readings, with either kit, by following the directions. If there is an unreasonable difference, have the water tested by a pool or spa professional, in order to better determine the more accurate test kit. I hope that I have been helpful.

Sincerely. Alan Schuster, 11/22/2005



► A ColorQ Digital Analyzer or a Test Strip Reader?

I am not good at matching colors and I like the idea of the digital ColorQ water Analyzer. I saw a test strip reader and that seems quite easy to use. How would you compare them? Thanks in advance, for your valued opinion.

Jerry G., Dallas, TX, 6/23/2008

Photometers, such as the ColorQ Digital Water Analyzers are capable of better reproducibility and accuracy than any test strip. A quality test strip, such as the LaMotte Insta-Test products, are able to provide test results that are reasonably and suitably accurate. The problem comes about in trying to match the colors to the color swatches. Using a strip reader does not impart greater accuracy and actually adds a few more variables. How long did you wait, before inserting the strip in the reader? How wet was the strip? Did water run, from one test pad to the another? What was the temperature? All of these variables, and more, affect the test results. An instrument, such as the ColorQ, is based on the same technology used in laboratory instruments and has a long history of successful use. Test strip readers may be convenient and fast, but are not capable of matching the performance of a quality photometer based tester. The feedback about the ColorQ line of testers has been highly favorable. The same cannot be said about dealer and consumer experience with test strip readers. I hope that this information will help you make the right choice.

Sincerely. Alan Schuster, 6/24/2008


► Questionable CYA Test Results?

First of all, thank you for your recent advice. Like many others that have come to rely on you, I feel I have finally found someone who can give me a credible answer to my questions/problems. On 4 Feb I used a Stain remover to remove light brown stains in a portion of my fiberglass pool. I followed the process and it worked as advertised. However, I am concerned about some dramatic changes in the chemical balance of my Pool. On 31 Jan, in preparation of my stain removal process, I had my water tested by a local Pool Company. This test showed a CYA level @ 83 (OK for my area of the Country) and a TA reading of 114. On 11 Feb, 3 days after completion of the stain removal process, I had my water tested at the same Pool Company. This test showed my CYA level @ 35 and my TA level @ 152. My question: Is it normal for a stain removal process to cause such a dramatic change in CYA and TA?

John G., 2/12/2008

Unless you replaced more than 1/2 of the water, the cyanuric acid results are questionable. There is no way that it should drop from 83 to 35 PPM, without water replacement. One of the numbers is wrong and I suspect the latter. If that test result is wrong, the TA could be wrong, as well.  Some dealers use test strips, for testing, which are capable of providing a suitably accurate, but not precise test results. Using a computer to read the test strip, does not necessarily provide greater accuracy. This could be a case or dealer error or a bad water sample. I would encourage you to become more self-sufficient, as it will save you money and possibly help you avoid problems. The LaMotte ColorQ PRO 7 Water Analyzer performs 7 important pool steps, while eliminating color-matching, look up charts and guesswork. And it is affordably priced! I am not sure what was done, in the way of stain treatment, but the pH have increased and. that would account for the higher TA, as it moves in the same direction as the pH. To get a truer TA reading, subject 30% of the CYA reading, from the TA test result. pH and TA are interrelated. Adjust the pH to 7.2-7.6, as needed. If the TA is under 80-120 PPM, add some TA Increaser (baking soda). If the TA is 80-120 PPM, you're perfect. If the TA is higher, you may not have to do anything. There is no compelling reason to have to lower the TA, if the pH is in range and there is no sign of scaling or cloudy water. If the calcium hardness is over 400 PPM, you might keep the pH closer to 7.2-7.4. There's little point in trying to get both parameters in range, when circumstances and nature are conspiring against you. I hope that this information is helpful.

Sincerely. Alan Schuster, 2/12/2008


► Choosing A Test Kit?

I see a lot more of the test strips around these days. I've never used them. Are they reliable?

Valerie S., Coram, NY, 6/12/2009

Test strips have come a long way in terms of reliability, accuracy and the number of different tests that can be performed. But, they are not all the same. The technology behind test strips is not simply impregnating a paper with some chemicals. Choose a brand that the dealer has confidence in. Make sure that the Test Strips are protected against moisture. While all manufacturers add a drying aid to the packaged strips, a better means of protection are the containers with a desiccant liner. All of the test strips can test for Free Chlorine and that is an important advance. This is the active germicidal form of chlorine and is a key test. The older OTO test kits did not test for Free Chlorine, but tested for the less important Total Chlorine. The convenience and lack of liquid chemicals makes them a choice of growing popularity. New testers, such as the ColorQ all-digital water analyzers offer greater reliability, without any color-matching or guesswork. Glad to be of help.

Sincerely. Alan Schuster, 6/12/2009


► Sampling - Testing Timeline?

My technicians are often ask by the customer to bring a water sample to our retail store and have it tested. The h/o will than call in for the results. How long can a water sample taken from a pool sit before having it tested?

Cheri D., 4/3/2007

Chlorine would be the most sensitive of the parameters. It will always be dropping and could be affected in a short time, depending on the quality of the water and the cleanliness of the container. Keeping the sample in a hot vehicle or in sunlight will only cause degradation to occur more quickly. Anything more than a few hours could be questionable. The other parameters are not as affected and little difference should be seen, in a tightly sealed container. Still, I suggest testing with a reasonably short time frame: 3-4 hours. I hope this information helps you set a reasonable guideline.

Sincerely. Alan Schuster, 4/2/2007

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