Alkalinity Testing - Importance of Testing Pool Total Alkalinity Daily

Total alkalinity testing of the water in your swimming pools and spas, should be done daily every week! This is the norm so as to ensure that it meets the recommended industry standards. Total alkalinity levels affects all other water parameters in swimming pools and spas. Because of this daily monitoring is required so that your pool water chemistry stays balanced.

The total alkalinity, in case you didn't know, is considered the governor or the buffer for pH control! It is so - because it is the buffering system for your swimming pool and spa water.

If at any time your test reveals that your total alkalinity is too low, you will experience what we in the pool industry call pH bounce with your water chemistry.

Total Alkalinity Testing For Swimming Pools And Spas

The test for the total alkalinity levels in swimming pools and spas is called a titration type test. This testing usually involves three different types of reagents. These reagents include:

  • A chlorine neutralizer. This reagent is the first of the three to be used. When beginning your spa or swimming pool water testing, you will add about two drops of this reagent to your water sample.

    This reagent is utilized in your testing because it removes any chlorine content from your water sample; which can interfere with the second reagent and give you a false reading.

    If you have a portable Taylor test kit, this reagent will be the one marked R-0007. If your water sample contains a chlorine level that is above 5.0, simply add more of the reagent until your water sample is completely neutralized of its chlorine content.

  • A total alkalinity test solution. This is the second reagent to be added next. It is also referred to as a color indicator. This indicator turns green if an alkalinity level is present in your water sample. Again if you are using a Taylor test kit, this reagent will be marked R-0008. When conducting your TA testing, you will add 5 drops of this solution to your water sample, give it a little swirl, and take your reading.
  • A calibrated solution of sulfuric acid (the titrant). This solution is added slowly drop by drop until the green color turns sharply to a red coloration. While adding the drops to your water sample, you will count the amount of drops until your sample changes color.

    Once you have the count of the amount of drops it took to change the color of your water sample, you would then multiply the results by ten (eg. 8 drops multiply by 10 equals 80 ppm). This is would be your actual total alkalinity level in your swimming pool. This means that each drop of the titrant test solution during your alkalinity test, equals 10 ppm of total alkalinity TA.

    At this stage of your TA testing, you are observing your pool water's resistance to the pH change. We call this part of your test, titrating your water sample. This TA test reagent is marked R-0009 in your Taylor test kit.

  • Factors That Can Interfere With Pool Total Alkalinity Testing

    As I mentioned earlier, you have to follow a sequence or process in order for you to get your desired TA readings. One problem that usually occurs is that you may experience a blue to yellow color change in your water sample instead of it going from green to red.

    This is usually an indication that your chlorine levels are extremely high in your swimming pool or spa. For you to get the correct reading for your total alkalinity, you have to neutralize all chlorine content form the water sample. And to achieve this, like I mentioned before, you simply add a few more drops of your R-0007 chlorine neutralizer until the desired result is achieved.

    Misconception When Testing Total Alkalinity In Swimming Pools And Spas

    There are some individuals who believe that we should subtract one third of our stabilizer (Cyanuric acid) from the final results of our total alkalinity testing. According to these folks, this equation would give us our true swimming pool or spa alkalinity result. Listen, nothing could be further from the truth.

    The stabilizer in your pool is cyanuric acid and it does not show any reaction to the chlorines that we use in the industry today. Your pool chemical stabilizer will not be registered as a carbonate alkalinity. Your pool total alkalinity is equal to the stoichiometric sum of the bases in solution.

    Carbonate alkalinity tends to make up most of your total alkalinity in a natural environment. This my friend, is due to the natural events and dissolution of carbonate rocks and the presence of carbon dioxide in our atmosphere.

    Common Natural Components That Can Contribute to Total alkalinity.

    These components include:

    • Borate.
    • Hydroxide.
    • Phosphate.
    • Silicate.
    • Nitrate.
    • Dissolved Ammonia.
    • The conjugate bases of some organic acids and sulfide.

    If you noticed, I did not mentioned anything about Cyanuric acid as a contributor. Therefore it will not affect the accuracy of your total alkalinity testing at all.

    Understanding Swimming Pool Total Alkalinity Testing Results

    The table below shows the results for different levels TA testing in the water of a swimming pool or spa.

    Corrosive EnvironmentWater BalanceCloudy Water
    When TA is too low: 50ppm - 80ppmWhen TA is just right: 80ppm - 110ppmWhen TA is too high: 110ppm - 140ppm.

    As pool and spa owners/operators, we need to maintain our TA levels between 80 and 120 parts per million. At this range, we will provide an optimal buffering environment (alkaline materials in solution) that is necessary, to control any pH swings in the water of our swimming pools and spas.

    Problems Resulting From Bad Total Alkalinity Readings

    When you ignore or don't conduct regular total alkalinity testing, you will experience some serious problems in your recreational water facility. For instance, if your total alkalinity readings are too low, you will have an unbalance pool or spa due to pH bounces or pH swings.

    This is when your pH swings up and down widely. This particular problem causes damage to swimming pools and their operating mechanical systems.

    If your TA is too high, the results can and usually is cloudy water in your pools and spas. This normally is a clear indication that your pool water is over saturated and needs to be corrected immediately. So, always try to maintain a proper TA level so that you control any possible pH swings.

    Hence you will safeguard your swimming surfaces and pool plasters from any attacks due to pH bounce. Simply because you are paying close attention on a daily basis by conducting regular total alkalinity testing.

    Alkalinity testing must be done frequently to determine the total alkalinity level.

    Return from Alkalinity Testing to Swimming Pool Care.

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