Understanding Pool & Spa Water Testing

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Test strips, Colorimeters, and test reagents are typically fast and easy to use for testing your pool water. You want them to produce results that are sensitive, accurate, and reliable. With …

Test strips, Colorimeters, and test reagents are typically fast and easy to use for testing your pool water. You want them to produce results that are sensitive, accurate, and reliable. With accurate results you can simplify the maintenance of swimming pools and spas, which makes your customers happy. This leaves more time to sell your skills to new customers; and word will spread that you know how to keep a sparkling clean pool.

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  • 1. UNDERSTANDING POOL & SPA WATER TESTING By Ivars Jaunakais Orlando Pool and Spa Show • February, 2010 R 021710
  • 2. BEFORE WE BEGIN, I WOULD LIKE TO ASK…
    • Are you new in the pool service business?
    • Have you done this for 5 years or less?
    • Have you done this for over 5 years?
    • Are you a pool builder?
  • 3. TODAY’S TOPICS
    • Recommended Florida health department standards for pool and spa water quality
    • Pool and spa water chemistry including chemicals, their uses, and sanitizer / disinfecting systems
    • Water testing methods and testing techniques
    • Pool water problems and treatment
  • 4. A. DO YOU MAKE YOUR DECISIONS ABOUT POOL OR SPA MAINTENANCE THIS WAY?
    • I can make decisions based entirely on information gathered
    • I can make decisions based on information rather than a gut feeling
    • I don’t take people’s feeling too much into account when I need to make an important decision
  • 5. B. DO YOU MAKE YOUR DECISIONS ABOUT POOL OR SPA MAINTENANCE THIS WAY?
    • I feel more comfortable if I consult an associate before a decision
    • I let my personal beliefs about pool maintenance impact my decisions
    • I am comfortable to make a decision if it “feels right” even if the decision isn’t supported by facts  
  • 6. TESTING IS IMPORTANT
    • Pools and Spas must be maintained in a conscientious way
    • Primarily for the safety of bathers
    • Liability
    • Good testing practices reaps financial rewards
  • 7. TESTING TOOLS
    • Test strips
    • Colorimeters
    • Test reagents
  • 8. GOALS
    • Happy customers
    • Produce accurate, and reliable results
    • Accurate results supports the correct maintenance saving time and money
    • The time saved will allow you to develop new customers
  • 9.
    • Over 12 million pools and 5 million spa in the United States all require maintenance
  • 10. THE GOAL is too maintain a pool or spa that …
    • is free from harmful microorganisms or pathogenic bacteria
    • is free from algae
    • is aesthetically pleasing (clean, clear, and inviting)
    • does not irritate the eyes, respiratory system, or skin of bathers
    • is not stained or suffering from discolored water
    • contains water that does not corrode
    • contains water that does not deposit or leave residue
    • does not have debris, scum, or foam floating on the surface
    • has no offensive odor
  • 11. 3 THINGS TO MAINTAIN A HEALTHY POOL OR SPA
    • Circulation
    • Filtration
    • Routine Cleaning and Maintenance
  • 12. STATE OF FLORIDA 64E-9.004 Operational Requirements
    • State Pool and Spa Regulation
    • Formerly 10D-5.133
    • Law took effect May 27, 2004
    • Can be found online - http://www.flrules.org/gateway/ruleno.asp?id=64E-9.004&Section=0
  • 13.
    • (1) Water Quality (a) Cross-connection prevention (b) Bacteriological quality (c) Clarity (0.5 or less NTU) (d) Chemical quality
    • Chemicals used in controlling the quality of the pool water shall be tested and approved using the National Sanitation Foundation (NSF) Standard 60, 1996a 1997, which is incorporated by reference in these rules and shall be compatible with other accepted chemicals used in pools.
    STATE OF FLORIDA 64E-9.004 Operational Requirements
  • 14.
    • The following parameters shall be adhered to for pool water treatment:
    • pH – 7.2 to 7.8.
    STATE OF FLORIDA 64E-9.004 Operational Requirements
  • 15.
    • The following parameters shall be adhered to for pool water disinfection treatment:
    • Free chlorine residual shall be 1 milligram per liter (mg/L) to 10 mg/L, inclusive, in conventional swimming pools and 2 mg/L to 10 mg/L, inclusive, in all other type pools such as spa-type pools and interactive water fountains mg/L free chlorine or 6 mg/L bromine.
    STATE OF FLORIDA 64E-9.004 Operational Requirements
  • 16. UNIT OF MEASUREMENTS
    • Primary unit of measurement for concentration is mg/L or parts per million ( PPM ) as more commonly used
    • 1 PPM would be 1 part of item measured per 1 million parts of pool water or just 0.0001 %
  • 17.
    • The following parameters shall be adhered to for pool water disinfection treatment:
    • Bromine residual shall be 1.5 mg/L to 10 mg/L, inclusive, in conventional swimming pools and 3 mg/L to 10 mg/L, inclusive, in all other type pools. Except that, the following maximum disinfectant levels shall apply to indoor conventional swimming pools: 5 mg/L free chlorine or 6 mg/L bromine.
    STATE OF FLORIDA 64E-9.004 Operational Requirements
  • 18.
    • When oxidation-reduction potential controllers are required
    • Water potential shall be kept between 700 and 850 millivolts.
    • Use of these units does not negate the manual daily testing requirement of subsection 64E-9.004(13), F.A.C.
    STATE OF FLORIDA 64E-9.004 Operational Requirements
  • 19. CHLORINE VS ORP READING
  • 20.
    • Cyanuric acid
    • 100 mg/L maximum in pools
    • 40 mg/L in spa pools
    • NOTE: Expect this level to be lower in the future
    STATE OF FLORIDA 64E-9.004 Operational Requirements
  • 21.  
  • 22.  
  • 23.
    • Quaternary ammonium
    • 5 mg/L maximum in pools or spas
    STATE OF FLORIDA 64E-9.004 Operational Requirements
  • 24.
    • Copper –
    • 1 mg/L maximum in pools or spas
    STATE OF FLORIDA 64E-9.004 Operational Requirements
  • 25.
    • Silver –
    • 0.1 mg/L maximum in pools or spas
    STATE OF FLORIDA 64E-9.004 Operational Requirements
  • 26.
    • The pool recirculation system must be operated
    • The pool water level must be maintained
    • All equipment and appurtenances should be in good repair
    STATE OF FLORIDA 64E-9.004 Operational Requirements
  • 27.
    • When use of a public swimming pool requires an admission or a membership fee, the most recent pool inspection report shall be posted in plain view of existing and potential members and patrons.
    • Sanitary facilities shall be maintained
    • Footbaths are prohibited
    STATE OF FLORIDA 64E-9.004 Operational Requirements
  • 28.
    • Test kits are required to be on the premises of all pools to determine
    • free active chlorine & total chlorine using N,N-Diethyl-p-Phenylenediamine ( DPD )
    • bromine levels
    • total alkalinity levels
    • calcium hardness levels
    • pH
    STATE OF FLORIDA 64E-9.004 Operational Requirements
  • 29.
    • The following test kits shall be provided if the corresponding chemicals are used:
        • Cyanuric acid
        • Sodium chloride
        • Quaternary ammonium
        • Copper
    STATE OF FLORIDA 64E-9.004 Operational Requirements
  • 30.
    • When silver is added as a supplemental disinfectant, a water analysis must be done every six months and be submitted to the department upon request.
    STATE OF FLORIDA 64E-9.004 Operational Requirements
  • 31.
    • A test kit may be used for multiple pools, provided the pools have common ownership and they are located on contiguous property.
    • The test kit shall be capable of measuring the level of disinfectant in the normal operating range.
    STATE OF FLORIDA 64E-9.004 Operational Requirements
  • 32.
    • The keeping of a daily record of information regarding pool operation, using the Monthly Swimming Pool Report – DH 921 3/98 , obtained from the local county health department, shall be the responsibility of the pool owner or operator.
    • http://www.doh.state.fl.us/environment/water/swim/download.html
    STATE OF FLORIDA 64E-9.004 Operational Requirements
  • 33.  
  • 34.
    • Customized report forms may be substituted provided they contain the appropriate information and are acceptable to the department.
    • Report shall reflect manually conducted pool water tests for pH and disinfectant levels at least once every 24 hours
    • Retained at the pool or submitted monthly as required by the local health department
    STATE OF FLORIDA 64E-9.004 Operational Requirements
  • 35.  
  • 36.
    • If fecal accident occur, the pool operator or owner shall consider the Centers for Disease Control's (CDC) “Fecal accident response recommendations for pool staff” found on the internet web site: http://www.cdc.gov/healthyswimming/
    STATE OF FLORIDA 64E-9.004 Operational Requirements
  • 37. DISINFECTION OF POOL AFTER FECAL ACCIDENT
  • 38. OTHER BODY FLUIDS
    • Vomit
        • Noroviruses germ hazard
        • Respond to the vomit accident as you would respond to a formed fecal accident, using CDC's recommendations
    • Blood
        • Germs don’t spread in properly chlorinated pool
        • There is no public health reason to recommend closing the pool after a blood spill
  • 39.
    • State Health Department Enforces these rules because swimmers leave behind:
        • Up to 50 ml of urine per swimmer (mostly by children)
        • 100 ml of sweat per swimmer each hour
        • Up to 100,000,000 bacteria per swimmer
        • Organics like sunscreen, deodorant, hair spray, etc
        • Greatest concern is a fecal or diarrhea accident (resulting in release of Ecoli, cryptosporidium)
    • NOTE: Although there is no such thing as urine-detecting dye, you can make signs that prey upon this misconception that a urine indicator exists
  • 40. WATER BALANCE
    • Defined as water that will neither scale nor corrode pool or spa surfaces and / or equipment
    • Corrosion involves the dissolving or wearing-away of a material
    • Scale is a white deposit or precipitate that builds up on fixtures, surfaces, and equipment
    • Balanced water is non-irritating to the eyes and skin of bathers, and allows the sanitizer to work effectively.
  • 41. WATER BALANCE 5 FACTORS THAT AFFECT IT
    • pH (PH)
    • Total Alkalinity (AL)
    • Calcium Hardness (CA)
    • Total Dissolved Solids (TDS)
    • Temperature
      • pH, AL, or CA is high , the water will deposit scale
      • pH, AL, or CA is low , the water will corrode
  • 42. WATER BALANCE - pH
    • pH is a very important factor
    • Affects all other chemical / balance parameters
    • Determines acidity of water and is measured on a scale from 0-14
    • pH of 7 is neutral
    • Below 7 is acidic (e.g. lemon juice)
    • Above 7 is basic or alkaline (e.g. baking soda)
  • 43. WATER BALANCE - pH
    • pH in the ideal range will be comfortable for the human eye at 7.5
    • Pool water is acceptable from 7.2-7.8
    • Ideal pH range is 7.4-7.6
    • Testing should be done DAILY !
    • A high pH, reduces Chlorine’s effectiveness
  • 44. pH VERSUS CHLORINE SPECIES
  • 45. WATER BALANCE - pH
  • 46.  
  • 47. WATER BALANCE - pH What causes pH to go up
    • Adding Alkali like Soda Ash
    • Alkali Sanitizers like Sodium Hypochlorite
  • 48. TESTING pH
    • Colorimetric visual tests
          • liquid test (using Phenol Red)
          • tablet test
          • test strips
    • Colorimetric test meter with pH indicator reagent
    • pH meter with electrode probe
          • Must be calibrated properly
          • Probe end is made of glass
  • 49. TOTAL ALKALINITY (AL)
    • The ability of the water to resist a change in pH
    • “ buffering capacity”
    • The sum of bicarbonates, carbonates, and hydroxide in the water
    • Water with an appropriate amount of AL will resist wide and rapid fluctuations in pH (called pH bounce)
    • Proper AL stabilizes pH
    • Bicarbonate buffers essentially neutralize acids and alkaline before they can affect the pH
  • 50. TOTAL ALKALINITY (AL)
    • If AL is low, pH will be easily affected by anything introduced into the pool
    • If AL is high, pH will be difficult to adjust (water will scale)
    • Total Alkalinity is the key to water balance and it is recommended that it should be adjusted FIRST, before pH
    • Anytime you add acid or alkaline to adjust the pool or spa AL, you will also be changing the pH, and vice versa
  • 51. TOTAL ALKALINITY (AL)
    • Test WEEKLY
    • Total Alkalinity is measured as Parts Per Million or PPM
    • Sanitizer used influences Alkalinity
    • Different sanitizers have different pHs
    • The ideal level is 80-100 PPM with sanitizers like Sodium, Calcium, or Lithium Hypochlorite
    • The ideal level is 100-120 PPM with sanitizers like Dichlor, Trichlor, Bromine, or Chlorine Gas
  • 52. TOTAL ALKALINITY (AL) Low Alkalinity can cause
    • Wide and rapid pH fluctuations
    • Corrosion of pool or spa and equipment
    • Skin / Eye Irritation
    • Low pH
    • Adding acid like Muriatic Acid will lower TA
  • 53. TESTING TOTAL ALKALINITY (AL)
    • Colorimetric visual tests
          • liquid test (titration)
          • tablet test
          • test strips
    • Colorimetric test meter with AL reagent
  • 54. ORDER OF pH & AL ADJUSTMENTS
  • 55. CALCIUM HARDNESS (CA)
    • Defined as the amount of Calcium Salts in the water (as Calcium Carbonate)
    • Term Calcium Hardness used because hardness in tap water is due to Calcium
    • Magnesium, barium and sulfate also can contribute to the Hardness
    • The water used to fill the pool will vary in its calcium content depending on your region of the country and city or well water
    • Ideal range is 200-400 PPM
  • 56. CALCIUM HARDNESS (CA)
    • Should be tested MONTHLY
    • Pool and spa water must have a certain amount of Calcium
    • Calcium Hardness, when outside the optimal range, can either allow corrosion to occur or cause scaling.
    • Make-up water with high calcium is “ hard water ”
    • Make-up water with low calcium is “ soft water ”.
    • Low hardness allows severe corrosion or pitting of calcium rich surfaces such as concrete, plaster, and grout.
  • 57. TESTING CALCIUM HARDNESS (CA)
    • Colorimetric visual tests
          • liquid test (titration)
          • tablet test
          • test strips
    • Colorimetric test meter with CA reagent
  • 58. CALCIUM HARDNESS (CA)
  • 59. TOTAL DISSOLVED SOLIDS (TDS)
    • Total Dissolved Solids or TDS is the total of all the dissolved material in the water.
    • TDS value is contributed and influenced by ions of Calcium, magnesium, sulfate, chloride, sodium, potassium, phosphate, nitrate, and all other ions; Alkalinity; Cyanuric Acid; and all Chemicals present in the water.
    • If it is dissolved in the water, it is part of TDS.
  • 60.  
  • 61. TOTAL DISSOLVED SOLIDS (TDS)
    • TDS levels need to be known because high levels increase undesirable events:
      • Algae growth despite adequate sanitizer
      • Corrosion despite the water being balanced
      • Cloudy water despite adequate filtration
      • Eye and skin irritation
      • Deposits on the pool wall
  • 62. TOTAL DISSOLVED SOLIDS (TDS)
    • Over time, TDS will increase in a pool
    • Factors that cause this include chemicals that are added, debris and dirt that blow or wash in, and the steady contribution of evaporation
    • If TDS reaches 1500 PPM above the level it was when the water was fresh, it is time to drain and replace the water (a maximum of 3000 PPM)
  • 63. TOTAL DISSOLVED SOLIDS (TDS)
    • TDS may double in a year
    • Not all disinfectant systems contribute equally to TDS
    • The use of Ozone will decrease the amount of chemicals that are added; and therefore slowing the rise of TDS
    • Another easy way to reduce TDS is to ask that people shower before they get into the pool or spa
  • 64. TESTING TOTAL DISSOLVED SOLIDS
    • Should test MONTHLY
    • Conductivity meter ($20 - $300) (can do thousands of tests)
    • Test strips ($0.30 to $0.50 per test)
    • Maximum is 1500 PPM over start-up TDS
  • 65. TEMPERATURE
    • Temperature is an important water balance factor but difficult to control
    • Pool water is usually held at between 78-82◦ F.
    • Spa water is held much higher at from 96-104◦ F
    • Thermometer used for testing
    • Test Frequency: Usually continuous monitoring
  • 66. LANGELIER SATURATION INDEX (SI)
    • Developed In 1936 by Wilfred F. Langelier
    • 5 factors influence the precipitation of Calcium Carbonate (the formation of scale). The five factors are pH, Temperature, Alkalinity, Calcium Hardness, and TDS.
    • AL and pH have significant influence on SI and are the 2 factors most often adjusted to change SI
  • 67. LANGELIER SATURATION INDEX (SI)
    • CA should always be adjusted if low
    • TDS has the least impact of the 5 factors
    • CA and TDS can be lowered effectively by partial draining of the pool or spa
    • Temperature is a large determining factor and is difficult to control, hold, and adjust
    • CA, TDS, and Temperature are factors we should monitor
  • 68. LANGELIER SATURATION INDEX (SI)
    • Mr. Langelier assigned a value to each of these factors and developed an equation.
    • SI = pH + TF (Temperature) + CF (Calcium Hardness) + AF (Total Alkalinity) – 12.1 (TDS)
  • 69. LANGELIER SATURATION INDEX (SI)
    • SI = pH + TF (Temperature) + CF (Calcium Hardness) + AF (Total Alkalinity) – 12.1 (TDS)
    • When result is 0, the water is said to be chemically balanced (ideal goal)
    • Negative values will have corrosive tendencies
    • Positive values will have scale tendencies
    • The acceptable range for the SI is -0.5 to +0.5 (Within this range, the water in a pool or spa is satisfactorily balanced)
  • 70. LANGELIER SATURATION INDEX (SI)
    • To calculate SI:
    • First, test and record the 5 parameters
    • Next, using Table 1, convert your test results for Temperature, Calcium Hardness, and Alkalinity into the equation plug-in factors TF, CA, and AF
    • TDS does not have a chart. Instead use 12.1 if TDS is from 0-1000 PPM 12.2 if from 1000-2000 PPM 12.3 if TDS is above 2000 PPM
    • pH is used without alteration
  • 71. LANGELIER SATURATION INDEX (SI) TABLE
  • 72. LANGELIER SATURATION INDEX (SI) EXAMPLE
    • pH= 7.8 Temperature= 84° Calcium Hardness= 300 PPM Total Alkalinity= 200 PPM TDS: 1800 PPM
    •   SI = pH + TF + CA + AF – 12.1 (TDS)
    • 7.8 + 0.7 + 2.1 + 2.3 – 12.2 = +0.7 (Scaling)
  • 73. LANGELIER SATURATION INDEX (SI)
    • To correct the water balance, we adjusted the Total Alkalinity to 100 PPM and the pH naturally lowered to 7.6
    • No change to Calcium Hardness level of 300 PPM is made (The Calcium Hardness cannot be lowered except by draining and refilling with water lower in Calcium Hardness)
    • Resulting SI will now calculate to be +0.2 or balanced!
  • 74. LANGELIER SATURATION INDEX (SI) EXAMPLE
    • pH= 7.6 Temperature= 84° Calcium Hardness= 300 PPM Total Alkalinity= 100 PPM TDS: 1800 PPM
    • SI = pH + TF + CA + AF – 12.1 (TDS)
    • 7.6 + 0.7 + 2.1 + 2.0 – 12.2 = +0.2 (OK)
  • 75. SANITIZER AND DISINFECTANTS
    • The pool environment is exposed to constantly introduced things
    • Two important things must be done:
        • Sanitize the water to kill microorganisms
        • Oxidize organic contaminants
    • A disinfectant is an agent that kills disease-causing organisms
    • A sanitizer is an agent that kills all microorganisms with impunity
    • Oxidation refers to the “burning up” of organic contaminants or waste products
  • 76. CHLORINE
    • The most popular sanitizer, disinfectant, algae killer, and oxidizer in the world is still chlorine
    • Inexpensive, safe (when used properly), and effective.
    • In a pool or a spa, chlorine pulls double-duty as a sanitizer, and as an oxidizer
    • Chlorine is most effective under certain conditions. The single most important factor is pH. The pH must be in the optimal range in order for chlorine to be effective
  • 77. CHLORINE
    • Effective against a broad range of microorganisms
    • Chlorine first used in 1908 for public health
    • More than 79,000 tons of chlorine are used per year in the United States and Canada to treat water
    • Monitoring chlorine is very important
    • Used in pools to protect people, water clarity and equipment
    • Several pathogens can be transmitted in water
    • Inactivation of pathogens depends on contact time
    • Public health requires pool water testing for Hypochlorous acid or free chlorine residual concentration
  • 78. GERM INACTIVATION TIME IN 1 PPM CHLORINATED WATER
    • pH 7.5, 77 ° F
    GERM INACTIVATION TIME E. Coli O157:H7 Bacterium Less than 1 minute Hepatitis A Virus About 16 minutes Giardia Parasite About 45 minutes Cryptosporidium Parasite About 15300 minutes (10.6 days)
  • 79. BACTERIA REGROWTH
  • 80. RISK OF ILLNESS
  • 81. RISK OF ILLNESS
  • 82. SOURCES OF CHLORINE Chemical Name Chemical Formula Form % Chlorine Chlorine Gas Cl 2 Gas 100% Calcium Hypochlorite Ca(OCl) 2 Solid 65-70% Sodium Hypochlorite NaOCl Liquid ~12%
  • 83. TYPICAL DEGRADATION RATE OF SODIUM HYPOCHLORITE
  • 84. ABOUT THE SOURCES OF CHLORINE
    • Despite their chemical and physical differences they all form hypochlorous acid
    • This change occurs when water is added
    • Hypochlorous acid (HOCl) is the actual disinfecting agent
  • 85. CHLORINE CHEMSTRY
    • The sum of Hypochlorous acid (HOCI) and Hypochlorite ion (OCI ¯) is called free chlorine, and the chemical equation or relationship is:
  • 86. HYPOCHLOROUS ACID REACTIONS
    • Two chemical reactions impact the performance of Hypochlorous acid as a disinfectant:
    • First reaction involves a hydroxide ion (OH¯)
    • OH¯ is available in aqueous solution especially when pH level is above 7 which causes Hypochlorous acid to form Hypochlorite ion
    • Hypochlorite ion is less than one third as effective a disinfectant as Hypochlorous acid
    • The next slide shows the relationship between pH versus chlorine species (Hypochlorous acid and Hypochlorite ion)
  • 87. pH VERSUS CHLORINE SPECIES
  • 88. CHLORINE REACTION
    • Second chlorine reaction is with ammonia (NH 3 ) and organic nitrogen compounds such as proteins and amino acids in the pool
    • A series of reactions occur that form chloramines
    • Chloramines are less effective as a disinfectant
    • Active chlorine can be transferred from inorganic chloramine to amine (organic) containing compounds
  • 89. COMBINED CHLORINE EQUATIONS
    • The sum of the chloramine species is called combined chlorine, and chemically created in the pool as follows:
  • 90. BREAKPOINT CHLORINATION
    • The process which eliminates both the combined chlorine and the ammonia problem responsible for creating the chloramine is called Breakpoint Chlorination
    • In the pool industry its called “Shock” also called “Super-Chlorination”
    • Shock is required daily, weekly or monthly and depends on a variety of considerations
  • 91. EUROPEAN DIN REGULATION
    • The German DIN regulation requires pools be drained:
            • Once a month or
            • ¼ every week or
            • 1/30 every day
    • Fresh water is added routinely which removes chloramines (organic & ammonia) and other contaminates
    • Universal use of ozone and / or UV for pools and free chlorine levels are maintained at 0.4 to 0.6 ppm
  • 92. TOTAL CHLORINE
    • Total chlorine is the sum of free chlorine and combined chlorine
    • Free chlorine and total chlorine are monitored by automated equipment and confirmed by poolside testing for swimmer protection
    • Total Chlorine = Free Chlorine + Combined Chlorine
  • 93. TO ACHIEVE GOOD TEST RESULTS
    • Test is acceptable or compliant (uses DPD )
    • Test is appropriate for the staff technical ability
    • Test is robust, reagents and equipment are reliable & stable
    • Test is not affected by interferences
    • Test is accurate when staff performs the test correctly
  • 94. US EPA ACCEPTED TEST METHODS (ACCEPTED BY FLORIDA HEALTH DEPARTMENT)
    • DPD -FAS Titrimetric Method
    • DPD Colorimetric Meter Method
    • DPD Colorimetric Visual Method
  • 95. DPD NOMENCLATURE
    • DPD-1 + DPD-2 is for free chlorine (liquid systems only)
    • DPD-1 is for Free Chlorine (Powders, tablets, test strips)
    • DPD-3 is KI (Potassium Iodide reagent) and applies to all except powders
    • DPD-4 is sum of DPD-1+DPD-2+DPD-3 (Total Chlorine)
  • 96. DPD DELIVERY METHODS
    • DPD-1, DPD-2, DPD-3 liquid reagents
    • DPD-1, DPD-3, DPD-4 tablets
    • DPD-1, DPD-4 powder pillows
    • DPD-1, DPD-3, DPD-4 reagent delivery test strips
    • (All meet 4500-CL G reportable method)
    • DPD is used for colorimetric or the DPD-FAS Titration methods to determine the chlorine concentration
  • 97. DPD CHLORINE TESTING
    • DPD methods have become preferred for chlorine measurement
    • The DPD methods determine concentration from the color formed when chlorine reacts with the DPD
    • DPD-FAS Titration method determines the chlorine by measuring the amount of FAS Titrant needed to bleach out the DPD-chlorine color formed
    • Most state health departments recommend or accept DPD tests because they are quick, enjoy wide acceptance and have US EPA approval
  • 98. TOTAL CHLORINE (TC) = FREE CHLORINE (FC) + COMBINED CHLORINE
    • Combined chlorine = TC - FC
    • Free chlorine = 1.58 ppm (FC)
    • Total chlorine = 1.89 ppm (TC)
    • Combined chlorine = 1.89 – 1.58 = 0.31 ppm Combined chlorine is above the recommend level of 0.20 ppm and suggests pool needs to be shocked: in this example ( 10 X 0.31 = 3.1 ) this pool can be shocked by increasing the pool chlorine level by 3.1 ppm
  • 99.
  • 100. CHLORINE TESTING
    • Test Frequency: Daily/ multiple times/day depending on bather load
    • Ideal is 2.0-4.0 ppm in a pool and 3.0-4.0 ppm in a spa
    • High Chlorine level can cause Eye / skin irritation
    • Low Chlorine level can cause Illness and Disease and Skin irritation from such as a bacterial rash
  • 101. COLORIMETER + LIQUID DPD POOLSIDE TESTING PROCEDURE
      • Rinse out photocell 3 times with pool water
      • Fill to 10 ml line with pool water sample
      • Cap cell, wipe cell wall
      • Place cell in colorimeter and zero meter
      • remove cell and uncap
      • add five drops of buffer DPD-1 solution
      • add five drops of indicator DPD-2 solution
      • cap cell and mix for a few seconds
      • wipe cell wall
      • place in colorimeter and read chlorine result
  • 102. COLORIMETER + DPD-1 POWDER PILLOW POOLSIDE TESTING PROCEDURE
      • Rinse out photocell 3 times with pool water sample
      • Fill to 10 ml line with pool water sample
      • Cap cell, wipe cell wall
      • Place cell in colorimeter and zero meter
      • remove cell and uncap
      • Tear open powder pillow and add DPD-1
      • Cap cell and mix for 20 seconds
      • Wipe cell wall
      • Place in colorimeter and read chlorine result
  • 103. COLORIMETER + DPD-1 TABLET POOLSIDE TESTING PROCEDURE
      • Rinse out photocell 3 times with pool water sample
      • Fill cell to 10 ml line with pool water sample
      • Cap cell, wipe cell wall
      • Place cell in colorimeter and zero meter
      • Remove cell, uncap cell,
      • Pour out water except for a few drops
      • Add DPD-1 Tablet and crush with tablet crusher
      • Add pool water back to 10 ml line
      • Cap cell and mix for about 20 seconds
      • Wipe cell wall
      • Place in colorimeter and read chlorine result
  • 104. COLORIMETER + DPD-1 TEST STRIP POOLSIDE TESTING PROCEDURE
      • Rinse out photocell 3 times with pool water
      • Fill meter cell to capacity with pool water
      • Turn meter on and Zero
      • Dip DPD-1 Test Strip into sample for 20 seconds with back and forth motion (Press “READ” button that begins countdown timer)
      • Read chlorine result
    • NOTE: This is a recent development in DPD testing
  • 105. NEW DPD METHODOLGY FOR POOLSIDE COMPLIANCE TESTING
    • Step 1 and Step 2
    • Rinse out photocell 3 times with pool water
    • Fill meter cell to capacity with pool water
  • 106.
    • Step 3
      • Turn meter on and Zero
    NEW DPD METHODOLGY FOR POOLSIDE COMPLIANCE TESTING
  • 107.
    • Step 4
      • Dip DPD-1 Test Strip into sample for 20 seconds with back and forth motion (Press “READ” button that begins countdown timer)
    NEW DPD METHODOLGY FOR POOLSIDE COMPLIANCE TESTING
  • 108.
    • Step 5
      • Read chlorine result
    • Free Chlorine = 1.58 ppm
    NEW DPD METHODOLGY FOR POOLSIDE COMPLIANCE TESTING
  • 109.
    • Step 6
    • Continue the test to determine the Total Chlorine concentration: Press “READ ” button and simultaneously dip eXact ® Strip Micro DPD-3 into the water sample for 20 second count down.
    • (During the 20 seconds constantly move the strip back and forth, which releases the Potassium Iodide reagent from the strip and mixes the sample)
    NEW DPD METHODOLGY FOR POOLSIDE COMPLIANCE TESTING
  • 110.
    • Step 7
    • At the end of the 20 seconds the meter will display “1” at which time you remove and discard the strip and the meter automatically reads and displays the total chlorine concentration, and stores the result in memory.
    • Discard sample and rinse with water before storage. This DPD test method is compliant for health department and US EPA requirements.
    • Total Chlorine = 1.89 ppm
    NEW DPD METHODOLGY FOR POOLSIDE COMPLIANCE TESTING
  • 111. FAS DPD POOLSIDE TESTING PROCEDURE
      • Rinse out cell 3 times with Pool water sample
      • Fill to 25 ml line with pool water sample
      • Add five drops of buffer DPD-1 solution
      • add five drops of indicator DPD-2 solution (or one scoop of DPD Powder)
      • Swirl to mix for a few seconds
      • Add one drop of FAS reagent, swirl to mix and observe color
      • Add next drop of FAS Reagent, swirl to mix and observe color (Repeated for a total of 14 drops)
      • When pink color disappears Multiple 0.2 by number of drops you have used to make color disappear This sample has (0.2 X 14 drops) 2.8 PPM Chlorine
    • NOTE: This procedure has a total of 20 steps for this water sample
  • 112. SPA WATER CHEMISTRY
    • Spas differ from pools because:
        • They have a much smaller volume
        • They run at a much higher temperature
    • Bather load (and sanitizer demand) is much heavier than in a pool
    • Smaller volume means that organics accumulate much faster, and the demand placed on the sanitizer is much higher
    • Greater sanitizer levels must be maintained (3-5 ppm for Chlorine, 4-6 ppm for Bromine) and testing must be carried out much more frequently – usually every 2 hours during periods of heavy use
    • Treatment is more demanding, because adjustments must be made more frequently, and measurements must be more precise.
  • 113. SPA WATER CHEMISTRY
    • Small volume and increased sanitizer demand means that in Chlorine spas, Chloramines accumulate much faster than in a pool
    • Spas must also be drained at regular intervals if water quality is to be maintained
    • High temperature (above 100 degrees F) rises chemical reactions occur more rapidly
    • Chlorine reactions occur more rapidly, causing more rapid depletion
    • High temperatures are conducive to the growth of certain disease-causing bacteria like pseudomonas aerginosa
    • High temperature contributes greatly to evaporation, which concentrates TDS (Total Dissolved Solids) in the water
    • Maintaining a spa presents unique challenges
  • 114. SPA WATER DRAINING
    • Draining helps prevent TDS and Chloramine accumulation
    • The Association of Pool & Spa Professionals recommends draining and refilling spas at intervals according to the following equation:
    • 1/3 X Volume of Spa (gallons)
    • _______________________
    • Bathers per day
    = Number of days between drainings 1/3 X 3000 30 = 33
  • 115. BROMINE
    • Bromine is a chemical relative of Chlorine
    • Used more commonly in spas because it is more stable at high temperatures
    • When Bromine combines with ammonia it becomes bromamine which is still an effective sanitizer (does not irritate eyes and skin)
    • Bromine and bromamine are measured together as Total Bromine (Typically with DPD-1 Reagent)
    •   More expensive than chlorine and can not be stabilized by cyanuric acid (rapidly dissipated by the sun)
    • Bromine comes most commonly in tablet form
    • Bromine as a sanitation agent can not be switched over to chlorine without completely draining and replacing the water
  • 116. BROMINE CHEMISTRY
    • Bromine's effectiveness dependent on the water's pH
    • Bromine breaks down in water forming Hypobromous Acid (HOBr) and Hypobromite Ion (OBr - ), the ratio of the two being pH-dependent
    • At high pH, more of the OBr - is present
    • Recommended pH levels are the same for bromine as for chlorine
    • HOBr is effective as an anti-algae agent
  • 117. BROMINE
    • Test daily or multiple times depending on bather load
    • Typical recommended levels: 2.0-4.0 ppm in a residential spa 4.0-6.0 ppm in a public spa
    • Advantages:
        • Safe and easily handled
        • Good sanitizer with no odor or irritation
        • Bromine efficiency is less dependent on pH
    • Disadvantages
        • More expensive than chlorine
        • Acidic; destroys total alkalinity
        • No stabilizer available (not recommended in Sun)
  • 118. BIGUANIDES (PHMB)
    • Biguanides are unique for the pool market
    • The term refers to a disinfectant polymer polyhexamethyline biguanicide (PHMB)
    • It is an effective sanitizer but not an oxidizer
    • Hydrogen peroxide must be applied as shock (monthly)
    • Ammonium-based supplement is needed weekly
    • PHMB concentrations need to be kept between 30 and 50 ppm and require a special test kit
    • PHMB cannot be mixed with chlorine or any other chemicals except those used as part of the package The result of doing so would be brown water and plaster stains
  • 119. BIGUANIDE (PHMB) TESTING
    • Test Frequency: Once per week or before swimming
    • Ideal levels: Concentration must be kept between 30 – 50 ppm
    • Advantages:
        • Useful in case of chlorine allergies
        • Less chemical smell
        • Easy on eyes and skin
        • Stable in sunlight
        • Less frequent testing and treatment
    • Disadvantages
        • Costlier than chlorine OR bromine
        • May clog filters
        • Not compatible with most pool maintenance chemicals
        • Not approved for commercial pools
  • 120. COMMERCIAL CHLORINE GENERATOR
    • Device that produces chlorine from a mixture of salt and water (brine) through electrolysis
    • Sometimes referred to as “salt generators”
    • Chlorine used is produced through the electrolysis of brine
    • Electrolysis uses two electrically-charged electrodes:
        • Anode (positively-charged)
        • Cathode (negatively-charged)
    • Electrolyzing salt, the electrodes are contained in different chambers because the result is chlorine gas and caustic soda, also known as lye, which should not be allowed to mix
    • The chambers are separated by a special membrane allowing sodium ions and electricity to pass through it, but not chloride ions or water.
  • 121. COMMERCIAL CHLORINE GENERATOR
    • Generator converts:120 or 240 volts AC to 4 or 6 volts DC
    • Residential pool unit requires about 20 amps
    • Electric current passing through the membrane from positive to negative splits the NaCl into chlorine gas and sodium
    • Electric current carries sodium ions through the membrane to the cathode chamber where it reacts with water to produce caustic soda and hydrogen gas
    • The hydrogen gas bubbles are vented off into the air
    • The chlorine gas in the anode chamber passes through a tube into the pool water
    • By-product of this process is a small amount of hydrochloric acid
  • 122. COMMERCIAL CHLORINE GENERATOR
    • Anode chamber must periodically be refilled with water and salt
    • The caustic soda can be re-used for adjusting the pool's pH balance
    • A typical chlorine generator designed for a 25,000 – 30,000 gallon pool requires 45-50 pounds of salt, which must be replenished 2-4 times per year.
    • A similar unit can generate Bromine by using Sodium Bromide instead of Sodium Chloride as a generating source
    • Since chlorine and bromine generators produce water sanitizers continuously during operation, it is less necessary for chemicals to be added to the pool or spa water
    • Water must still be tested for sanitizer levels
    • Equipment is expensive to buy and install.
    • In addition to regular testing, chlorine or bromine generators require salt level determination (Chloride or Bromide)
  • 123. SALT TEST KITS
    • Colorimetric visual tests
          • liquid test (titration)
          • tablet test
          • test strips
    • Colorimetric test meter with SALT reagent (typical testing requires a dilution step)
  • 124. OZONE GENERATION
    • Ozone is negatively-charged oxygen atoms
    • Occurs naturally in the atmosphere, through the action of lightning
    • Non-toxic
    • Useful water purifier, used for decades in municipal water systems
    • Reduces the amount of chemicals needed to combat algae and bacteria
    • Ozone has no effect on the pH balance, alkalinity or TDS of the pool water, but it does NOT eliminate the use of chlorine
    • Breaks down immediately on contact with water-borne contaminants, but does not combat algae formation on pool and spa walls
  • 125. OZONE GENERATION
    • Can reduce the use of biocides and algaecides in a pool, it is not a complete solution
    • Ozone generation involves the use of an ultraviolet (UV) or Corona Discharge (CD) unit which converts Oxygen (O2) to Ozone (O3)
    • Advantages:
        • Reduces the use of sanitizing chemicals
        • No effect on water balance
    • Disadvantages:
        • Ineffective against algae
        • High installation expense
  • 126. IONIZATION OF COPPER AND SILVER
    • Ionization is used for sanitation and has no effect on pH balance, alkalinity or TDS
    • Copper ions destroy algae; silver ions have a static effect on bacteria
    • Ionizers use electricity to generate metal ions in the pool water
    • Voltage generates positive ions
    • Typical location of the electrodes is in an “ion chamber” located in line between the pump and filter
    • A control box varies the low-voltage DC charge (12-36 volts, .5-1 amp) to the electrodes that regulates the concentration of ions.
    • One system may use only copper electrodes; another system may use a copper and a silver electrode which produce both copper and silver ions
  • 127. IONIZATION OF COPPER AND SILVER
    • Excess copper ions in the water can cause staining
    • Copper level in the range of 0.15-0.2 ppm is recommended
    • The ion level is adjusted by changing the current flow across the electrodes, using a manual dial on the control unit
    • Ionization is not sufficient for complete sanitation of the pool water but can reduce the need of chemicals
    • Ionization manufacturers recommend weekly additions of an oxidizer (like potassium peroxymonosulfate) to remove organic contaminants and assist in combating algae
    • Advantages:
        • Can reduce use of sanitizing chemicals
        • No effect on water balance
    • Disadvantages
        • Copper ions cause staining
        • High installation cost
  • 128. COPPER TESTING
    • Small concentrations of copper in the water can be beneficial as a biocide
    • Excess copper causes staining that can be very difficult to remove
    • Testing for the presence of copper can provide early warning of plumbing erosion or corrosion
    • If pool surfaces are being stained green or blue-green, or if bathers are complaining of green hair or blue fingernails, the water usually contains excess copper.
    • Copper concentrations can be tested with a visual colorimetric test, a liquid test, test strip, or colorimeter with Cu reagent
  • 129. IRON
    • Iron in the pool water can be a source of black or red stains on pool surfaces
    • Above 0.1 ppm will cause the water to have a bad taste
    • Secondary drinking water regulation by the USEPA is set at 0.3 ppm (more of an esthetic than health issue)
  • 130. WHAT IS IRON?
    • Iron is one of the most commonplace elements on Earth. Second most abundant metal (after aluminum) and fourth most abundant element.
    • Iron has the chemical symbol “Fe.”
    • Because iron is very reactive, it does not exist on its own.
    • Iron is so common in the earth’s crust that at least a trace is found in almost everything.
    • Used in medicines.
  • 131. IRON BECOMES AN ION
    • Fe  Fe +2 (Ferrous) + 2 electrons
    • Fe  Fe +3 (Ferric) + 3 electrons
    • Fe +2 + Cl 2  FeCl 2 (Ferrous Chloride)
    • 2Fe +3 + Cl 2  2Fe 2 Cl 3 (Ferric Chloride)
    • 4Fe +3 + 3O 2  2Fe 2 O 3 (Iron Oxide)
  • 132. HOW IRON GETS IN THE WATER
    • Make-up water drawn from a well
    • If a metal component that contains iron begins to rust it releases iron into the pool water
  • 133. IRON REMOVAL
    • Chelating or Sequestering Agents work best
    • They prevent any iron coating on the pool walls
  • 134. IRON TESTING
    • Colorimetric visual tests
          • liquid test
          • tablet test
          • test strips
    • Colorimetric test meter with FE and Reducing Reagents
  • 135. HOW AN IRON TEST WORKS
    • Iron testing most frequently uses TPTZ powder pillows, test strips, or tablets containing in one unit, reducing agents, buffer and TPTZ indicator
      • Ferric iron + reducing agent = ferrous iron
      • TPTZ + ferrous iron = blue color
    • There is an inherent flaw in this test methodology. Turbidity issues (and most iron samples have turbidity) are addressed by adding an optional step, which is often ignored
    • This step, when ignored, can result in false low readings.
  • 136. PHOSPHATE IS?
    • Phosphorus is about 0.12% in the earth’s crust
    • Human bones and teeth contain a large amount of calcium phosphate
    • Muscle, nerves and brains of animals, contain complex organic compounds of phosphorus, which are formed from vegetable matter
    • Red phosphorus is used for pyrotechnics and for the manufacture of safety matches and fertilizers
    • Phosphate is an essential nutrient and food for algae growth
  • 137. PHOSPHATE BECOMES AN ION
    • P  P +5 + 5 electrons
    • 4P + 5O 2  2P 2 O 5
    • P 2 O 5 + 3H 2 O  2H 3 PO 4
      • (phosphoric acid)
    • H 3 PO 4 + H 2 O  H 3 O + + H 2 PO 4 – (dihydrogen phosphate)
    • Ca(H 2 PO 4 ) 2 Calcium Dihydrogen Phosphate is known as “Super Phosphate of Lime” and used as a fertilizer
  • 138. HOW PHOSPHATE GETS IN WATER
    • Runoff from lawns
    • Rain water
    • Bathers (sweat and urine)
    • Pool treatment chemicals
    • Blown in leaves and debris (soil and rock)
  • 139. ANOTHER WAY TO CONTROL ALGAE GROWTH
    • In Florida, Catfish are used to eat the algae in abandoned pools
  • 140. CONTROL ALGAE BY CONTROLLING PHOSPHATE
    • Pool water should be regularly refreshed with a fraction of new make-up water daily or weekly
    • Increase swimming pool chlorine level
    • “ Flock” the phosphate with a phosphate flock salt and vacuum
  • 141. SALTS THAT REMOVE PHOSPHATES
    • Iron salts (undesirable in pools) Used by municipal water and wastewater plants. Very effective in removing phosphate. HPO 4 -2 + Fe +3  FePO 4 ↓ + H +
    • Aluminum salts (inexpensive) Effective for levels above 1000 ppb. Does not remove phosphate below 100ppb. HPO 4 -2 + Al +3  AlPO 4 ↓ + H +
    • Lanthanum salts (expensive) Effective for maintaining low levels of phosphate. Easier to use and apply than Aluminum salts. Can drop phosphate levels below 100 ppb. HPO 4 -2 + La +3  LaPO 4 ↓ + H +
  • 142. LATHANUM SALTS (chloride & sulfate)
    • Form a water insoluble Lanthanum Phosphate precipitate
    • Easily removed by the pool filter media
    • In high concentrations, salts will not cause cloudy water or staining of the pool
  • 143. HOW TO KEEP POOLS PHOSPHATE FREE
    • Avoid lawn/garden run-off from entering the pool
    • Remove leaves promptly
    • Keep phosphate below 0.10 ppm (100 PPB)
    • Test the make-up water for phosphate
    • Test the pool water phosphate levels regularly
    • Preferred colorimetric test uses molybdate reaction with phosphate in mild acid solution to form molybdophosphoric acid (heteropoly blue complex)
  • 144. PHOSPHATE TESTING
    • Colorimetric visual tests
          • tablet test
          • test strips
    • Colorimetric test meter with PO 4 reagent
  • 145. TURBIDITY
    • Another word for cloudiness
    • Caused by several factors:
          • Body-waste contamination
          • Non-organic suspended solids
          • Algae
          • Chemical imbalance
    • Turbidity is most commonly measured with a “turbidometric” meter – and is very accurate
    • Can also be tested with a colorimeter (less accurate)
  • 146. TEST METHOD Turbidometric Tester
    • Measures the relative cloudiness, or turbidity of the water in NPT units
    • Turbidometric testing can be determined by a visual method but only at higher levels
    • Commonly measured with a Turbidometric meter which is measured by the light reflected from the undissolved materials in the water at a 90 degree angle
    • Colorimeter can also make this measurement as a transmission measurement but with less accuracy
  • 147. BACTERIA
    • Bacteria are microorganisms that enter pool water through rain, blown-in contaminants, and the bodies of the bathers themselves. As previously discussed, the most important function of sanitizers is to combat these microorganisms.
    • Chlorine is introduced into a pool it breaks down into hypochlorous acid (HOCL) and hypochlorite ions (OCL-). Both of these kill bacteria by attacking the bacterial cell walls and oxidizing everything inside. Hypochlorous acid is able to oxidize most bacteria organisms in several seconds while hypochlorite ions can take over 30 minutes. Both can get the job done, but the time required.
    • Bacteria testing requires culturing the water.
  • 148. 18 MINUTE BACTERIA TEST
    • Commercial test methods include Immunological test that can confirm bacteria levels below 1000 colonies per ml run in 18 minutes
    • Reduces liability
    • Gives confidence that pool is safe to reopen
    • The Quick™ Bacteria Test is an antibody-based rapid test kit for the presence of bacteria in swimming pools, spas and rivers, lakes or streams used for swimming. The Quick™ Bacteria Test detects E.Coli, species of Salmonella, Shigella, Enterobacter, Kliebsiella, and many other Coliform and non-Coliform bacteria.
  • 149.  
  • 150.  
  • 151.  
  • 152.  
  • 153.  
  • 154. COLORIMETIC TESTS
    • There are four basic colorimetic methods used in testing pool and spa water:
      • Colorimetric tests use a Colorimeter and reagent delivery device such as: liquid, powder, tablet, and test strip
      • Colorimetric visual using titration (counting drops)
      • Colorimetric tests use a reagent delivery device such as: liquid, powder, tablet, or test strip with a tube and a comparator color chart
      • Colorimetric visual test strips are used most commonly for testing these three parameters: Free Chlorine, pH, Alkalinity levels
  • 155. LIMIT OF DETECTION (LOD)
    • Applies more to instrument measurements
    • Definition: MDL (minimum detection level) of concentration that can be consistently detected
    • For analytical tests LOD is typically calculated as 3 times the background noise
  • 156. TEST METHOD #1 Colorimeter and Reagent Most accurate DPD method
    • Colorimeters use colorimetric or precipitation chemistries and the color (or precipitate) is measured by an electronic instrument
    • No visual color matching
    • They measure transmittance of light at a given wavelength through the reacted water sample
    • Most accurate of all tests
  • 157. TEST METHOD #2 Colorimetric Visual using Titration Commonly used DPD method
    • Titrations use colorimetric chemistries that require visual color change interpretation
    • Color change can be difficult to judge
    • Accurate counting of drops is required
    • Technique dependent (swirling)
    • Math required
  • 158. TEST METHOD #3 Colorimetric reagent with color chart comparator
    • Inexpensive reagents
    • Gives only minimum resolution
    • Reagents may have stability issues
    • Requires good visual judgment
  • 159. TEST METHOD #4 Colorimetric visual test strips with color chart
    • Quick and easy
    • Inexpensive
    • Suitable for screening
    • Good shelf life
    • Does not use DPD
  • 160. TEST METHODS AND EQUIPMENT Considerations for Kit
    • Accuracy (0.03 to 3 or more)
    • Resolution (0.01 to 0.8 or more)
    • Selectivity (test reacts with the right ion)
    • Dynamic Range (6.0 to 9.0 for pH; 0.01 to 11.0 for Chlorine)
    • Limit of Detection (LOD)
  • 161. TEST KIT PERFORMANCE IN A LAB
    • Analysis will provide good results in a Laboratory setting
    • A lab is a controlled environment where Reagent stability is assured
    • Recalibration of test kit reagents or kit performance can be easily confirmed
  • 162. TEST KIT PERFORMANCE POOLSIDE ( Challenges)
    • Test kits and instruments at poolside operate under harsh environmental conditions
    • Temperature, humidity, wind can have a great deal of affect on results and operator
    • Distractions like loud noise and high activity
    • For some tests (especially Liquid reagents) stability is affected by elevated Temperature and Sunlight
    • Unfortunately precise results are a challenge at poolside
  • 163. TEST METHODS AND EQUIPMENT Considerations for Method
    • Price per test ($0.02 to $0.30 up to $10)
    • Time to run test (30 seconds to 5 minutes)
    • Easy to run test (Little or no operator training required)
    • Kit is portable and stabile
    • Results are accepted by Health Department
  • 164. TESTING TECHNIQUES (best practices)
    • Let the circulation system run before taking your sample, or manually stir the water in the sample area
    • Rinse the sample vial two or three times with the pool water before taking your sample
    • Sample the water from 18 inches below the surface (especially important for the Free Chlorine measurement)
    • Do not take a water sample from near the return lines
    • Make note (or at lease be aware approximately) of the temperature of the water you are testing. Very cold or very hot water will affect colorimetric tests
    • Perform your tests as soon as possible after collecting the sample (immediate testing is required accurate for Free Chlorine results)
    • If collecting samples for later testing, handle carefully to avoid contamination and fill bottle to capacity and seal tightly
  • 165. TESTING GUIDELINES (best practices)
    • Pay careful attention to expiration dates on reagents and test strips
    • Keep reagent containers tightly capped and in a cool, dark place
    • Don't swap/mix the caps on reagent bottles, or the chemicals may get cross contaminated
    • Where required carefully measure volume of the water sample to be tested (Measure the bottom of the sample meniscus, not the top at the fill mark)
    • Don't interchange sample vials or cells
    • Follow the manufacturer’s test directions carefully
  • 166. TESTING GUIDELINES (best practices)
    • Add reagents carefully – make sure the drops you add to the sample are equal and full-sized
    • Mix reagents with test samples thoroughly
    • Match the visual test results under the right conditions:
        • Proper light
        • Do not wear sunglasses
        • Read the colors against an appropriate background
        • Do not match colors in bright sunlight
    • Record results and keep a log book at each pool or spa
    • Never add reagents to the pool for flash testing (invalid)
    • Never dispose used sample and reagent in the pool
    • Rinse sample vials / cells well immediately after testing
  • 167. HELPFUL RESOURCES
    • Book: Pool Chlorination Facts by Robert W. Lowry
    • Book: Intermediate Training Manual Part 1-Chemicals by Robert W. Lowry
    • Book: The Ultimate Guide to Pool Maintenance by Terry Tamminen
    • Book: The Pool Maintenance Manual by Terry Tamminen  
    • Internet: Florida Health Dept: http://www.doh.state.fl.us/Environment/water/swim/index.html
    • Internet: CDC   http://www.cdc.gov/healthyswimming/
  • 168. STRIVE FOR BEST RESULTS
    • Customer wants it
    • State Health Department requires it.
    • Liability for bad results
  • 169. Any Questions? Ivars Jaunakais – Chief Analytical Chemist [email_address] www.sensafe.com THANK YOU FOR YOUR ATTENTION !