Proper Testing Procedures in

Salt Water Pools (The Importance of Accurate Results)

By Ivars Jaunakais

•  Summary of the different devices for pool testing"•  Electronic advances are changing the way we do things"•  Changes in the horizon due to NSF 50 and MAHC"•  Very important considerations for salt pool testing"•  How to verify that you, the test method, and reagent is giving

you correct answers"

TOPICS

•  Proper pool maintenance requires testing for Balanced Water "

•  In the near future you may only consider using NSF 50 certified tests "

•  Chlorine and pH testing is performed most frequently "

•  The pool industry is evolving rapidly and skilled Pool Service Technicians are needed."

•  Wall Street Journal claims that 90% of businesses do business today differently then 5 years ago"

"

POOL TESTING IS VITAL

"• MAHC requires pool side testing every 4 hours for pH, Free Available Chlorine, and Combined Chlorine •  MAHC testing for Total Alkalinity and Salt (Weekly) and for Calcium Hardness and Cyanuric Acid (Monthly) • MAHC testing for Copper and Silver (Daily), and for TDS (Quarterly) • Other tests like Phosphate at this time not addressed by MAHC or NSF 50

TESTING SCHEDULE

•  Salt Pool Systems require Poolside testing to verify chlorine output

•  It makes sense to use a Poolside test that is as simple as possible

•  Often Poolside testing is challenging •  Temperature, humidity, sunlight,

wind, rain can affect results and even distractions such as poolside activity and noise

POOLSIDE TESTING

•  Cost (varies $0.03 to over $1.00 per test) •  Time to run test •  Ease of use •  Stability of test reagent(s) •  Commercial Pools: Does test meet Health

Department regulations? •  Resolution and Accuracy and Precision

POOLSIDE TEST CONSIDERATIONS

•  pH meters •  Colorimeters (Photometers) & reagents •  Drop Counting Titration •  Visual Comparator tests •  Test Strips

POOLSIDE TESTING METHODS"

You need right conditions:"1. Proper lighting"2. Don’t wear sunglasses"3. Read colors against an

appropriate background"4. Don’t match colors in

bright sunlight"

For visual COLOR matching in POOLSIDE TESTING

For Visual COLOR matching in POOLSIDE TESTING

• When test involves visual color matching then there is the small but real issue of color blindness

COLOR BLINDNESS

Over 32 million Americans (8% of men) are color blind"

COLOR BLINDNESS

CONSIDER THIS ABOUT THE POOLSIDE TEST METHOD YOU USE

• Resolution correlates to test Accuracy. •  After 40 years I personally have come to a

realization that my lab equipment if properly calibrated (precision is confirmed), then the unit will typically give an accuracy on average of about 3 times the resolution of the test. Similar accuracy and resolution relationships of 3 to 1 have been reported in ANALYTICAL CHEMISTRY JOURNALS

RESOLUTION EFFECTS ACCURACY!

Resolution 1 ppm Resolution 0.1 ppm

RESOLUTION EFFECTS ACCURACY!

Digital Devices can have resolution of 0.01 ppm for Free Chlorine and so accuracy of +/- 0.03 ppm can be expected from a calibrated photometer. Accuracy becomes very important when you want to know when the Combined Chlorine levels are above 0.2 ppm (MAHC action level is 0.4 ppm) which triggers: 1. Superchlorination (Shock) 2. Water exchange or 3. Bathers adhere to better Bather hygiene

• pH meter (0.01 or 0.1)"• Photometric (0.1)"• pH comparator (0.2)"• Test Strips (0.3 or 0.4)"

pH Test Methods (resolution)"

•  DPD Photometric Digital Meter (0.01ppm)"•  ORP Digital Meter reads above 650mV"•  DPD-FAS Drop count Titration (0.2 ppm)"•  DPD Visual Color Comparator (1 ppm)"•  Chlorine Test Strip (1 to 3 ppm)"

"

CHLORINE TEST METHODS(resolution)"

• Photometric (1 ppm)"• Titration (10 ppm)"• Test Strips (40 ppm)"

TOTAL ALKALINITY TEST METHODS (resolution)"

• Photometric (1 PPM)"• Titration (20 PPM)"• Test Strips (50 PPM)"

CALCIUM HARDNESSTEST METHODS (resolution)"

• Photometric (1 ppm)"• Visual black dot comparator (20 ppm)"

• Test Strip (50 ppm)"

CYANURIC ACID TEST METHODS (resolution)

NSF 50 ACCURACY SCALE L1,L2,L3

TYPICAL ACCURACY OF POOLSIDE TESTING METHODS

SALT

•  Salt in pool water also called salt chlorination •  Dissolved salt (1,800–6,000 ppm) is needed for

the chlorination system •  The chlorinator uses electrolysis to break down

the salt (NaCl +H2O = NaOH + HOCl). •  The resulting chemical reaction eventually

produces Sodium HypoChlorite equivalent or NaOCl

•  Saltwater pool utilizes a chlorine generator instead of direct addition of chlorine.

COMMERCIAL CHLORINE SALT GENERATOR

•  Device that produces chlorine from a mixture of salt and water (brine) through electrolysis

•  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.

SALT • The pool's pH tends to go up so monitor pH accurately • A chlorine generator designed for a 25,000 – 30,000 gallon pool requires 45-50 pounds of salt, which may require additions of Salt 2 to 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, there is a better chance that you will add less chemicals to the pool or spa water • Equipment is expensive to buy and install • In addition to regular testing, chlorine or bromine generators require monthly salt level determination (Chloride or Bromide)

SALT TEST KITS (resolution)

•  Photometric with SALT reagent (10 PPM) •  TDS meters with Salt Algorithm (10 PPM) can be used but at

least once a year verify salt level with a second method (test strip or photometric)

•  Salt Test Strips (500 PPM) and Salt Titrating Strip (100 PPM) •  Most Salt System Manufacturers recommend accuracy to

within 500PPM of the Salt level

PHOSPHATE

•  Phosphorus is 0.12% of the earth’s crust"•  Human bones and teeth contain 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 for algae growth"•  Phosphate Testing is challenging below 0.2PPM (200ppb)"

HOW PHOSPHATE GETS IN WATER

•  Runoff from lawns "•  Rain water "•  Bathers

(sweat and urine)"•  Pool treatment chemicals"•  Leaves and debris " that is blown in"

CONTROL ALGAE BY CONTROLLING PHOSPHATE

•  Municipal City make-up water most likely contains 1PPM phosphate"

•  Increase swimming pool chlorine level if phosphate is present. "

•  “Flock” the phosphate with a phosphate flock salt and vacuum."

•  Rain water is usually OK "

CONTROL ALGAE BY CONTROLLING PHOSPHATE

•  A well maintained pool with clean water but 2.1 ppm phosphate looked like this...

•  This pool was perfectly maintained with FC of 1.21PPM, pH of 7.5, CY of 30 PPM, AL of 119PPM, CA of 324PPM

SALTS THAT REMOVE PHOSPHATES

•  Iron salts (undesirable in pools) Used by municipal water and wastewater plants. Very effective in removing phosphate.

HPO4-2 + Fe+3 → FePO4↓ + H+

• Aluminum salts (inexpensive) Effective for levels above 1000 ppb. Does not remove phosphate below 100ppb.

HPO4-2 + Al+3 → AlPO4↓ + 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.

HPO4-2 + La+3 → LaPO4↓ + H+

LATHANUM SALTS (chloride and sulfate)

•  Form a water insoluble Lanthanum Phosphate precipitate"•  Easily removed by the pool filter media"•  Even with high Phosphate concentrations, salts will not

cause cloudy water or staining of the pool"

KEEP Salt POOLS PHOSPHATE FREE

•  Test the pool water for phosphates regularly"•  Avoid lawn/garden run-off from entering the pool"•  Remove leaves promptly "•  Keep phosphate below 200 ppb (0.2 PPM)"•  Test the make-up water for phosphate "•  Preferred photometric and colorimetric tests use the

chemical reaction of molybdate with phosphate in mild acid condition to form molybdophosphoric acid or heteropoly blue complex"

PHOSPHATE TESTING (resolution)

•  Digital Photometric 0.01 PPM (or 10 PPB) resolution •  Test Strip with Comparator 0.1 PPM (or 100 PPB)

resolution •  Ideally keep level at 0.1PPM (100 PPB) or less •  If Chlorine is maintained above 4PPM and CY at 40PPM

pool can tolerate 0.5PPM (500PPM) phosphate without algae problem.

•  For Salt pools try to keep phosphates below 200 PPM

DIGITAL TEST DEVICES

DIGITAL TEST DEVICE – pH METER

Suggested Internet Price for Meter - $200 Frequent Calibration Required Test Time – 3 minutes for 6 tests Made by Solaxx

DIGITAL TEST DEVICE – TDS/pH PEN

Suggested Internet Price for TDS Pen - $147 Suggested Internet Price for pH Pen - $140 Suggested Internet Price for pH/TDS Pen - $280 Test Time – 1 minute per test Frequent Calibration not required Made by Myron L Company

•  Use colorimetric or precipitation chemistries and the color (or precipitate) is measured by a digital instrument that measures light transmission through sample

•  Recalibration not required since •  Concentration is determined by the amount of light that is

transmitted through the reacted pool water sample •  Chlorine has 0.01 ppm resolution; +/-0.03 ppm accuracy •  pH has 0.1 ppm resolution; +/- 0.2 ppm accuracy

COLORIMETRIC/PHOTOMETRIC DIGITAL TEST DEVICES

COLORIMETIC/PHOTOMETRIC DIGITAL TEST DEVICE - SPIN

COLORIMETIC/PHOTOMETRIC DIGITAL TEST DEVICE - SPIN

COLORIMETIC/PHOTOMETRIC DIGITAL TEST DEVICE - SPIN

Suggested Price for Meter and Software - $995 Chlorine/Bromine disk - $1.75 Test Time – 3 minutes for 9 tests Made by LaMotte in USA Patent Pending

PHOTOMETRIC DIGITAL TEST DEVICE -

iDIP

BlueTooth device connects with iPhone, iPad, or Android SmartPhone that can do over 30 Water Quality Tests and each test automatically is linked with Date, Time of day, and location (GPS)

COLORIMETIC/PHOTOMETRIC DIGITAL TEST DEVICE - iDip

DIGITAL TEST DEVICE - iDip

Suggested Price for Meter and includes a FREE app - $180 $0.09 to 0.40 per test Test Time about 30 seconds per test 30 tests available Made by Industrial Test Systems in USA Patent Pending

DIGITAL PH METER CHLORINE PHOTOMETER

Combo TEST DEVICE – EZDOO

Internet Price for EZDOO Meter - $250 Weekly pH calibration needed FC, TC, pH tests in 2 minutes for $0.30 Manufactured in Taiwan by GonDo

•  Fast and inexpensive •  Suitable for screening

•  Strips have good shelf life

•  pH resolution is 0.1 and accuracy is about 0.4

•  Chlorine resolution is 0.1 ppm and accuracy is about 1 ppm

•  Available for many parameters

•  Calibration for each new lot of strips required

DIGITAL TEST STRIP READER-WAVE III

DIGITAL TEST STRIP READER – WAVE III

Suggested Price for Meter and Software - $950 Cost for one 6 way Test Strip is $0.95 Test Time – 2 minutes for 6 tests Made by Homeport Computing in USA

IDEAL LEVELS FOR SALT POOLS

TEST IDEAL LEVELS pH 7.4 to 7.6 (MAHC 7.2 to 7.8) Free Chlorine 1.0 - 3.0 ppm (Maximum of 10 ppm) Cyanuric Acid 20 to 60 ppm (MAHC below 100 ppm)

Total Alkalinity 80 to 120 ppm (MAHC 60 to 180) Calcium Hardness 200 to 400 ppm (MAHC maximum level

is 1000 ppm) Copper/Silver 1.3 ppm/0.10 ppm (from MAHC) Saturation Index -0.2 to +0.2 (regular pools -0.5 to +0.5) Combined Chlorine

0.2 ppm (MAHC action level is 0.4 ppm)

USING STANDARDS

TO CONFIRM ACCURACY OF YOUR DIGITAL DEVICE USED

AS WATER QUALITY TEST DEVICE

• Standards are solutions with known values that are used by laboratories to verify the accuracy of their test

• Standards are now available for pool service professionals

WHAT IS A “STANDARD?”

•  Verifies the accuracy of your test "•  Verifies operator is running test correctly"

•  Verifies reagents are functioning good""

WHY USE A “STANDARD?”

• Food, Medical, and Drinking Water Agencies (Government regulators and inspectors) require that Testing equipment be confirmed by Standards regularly."

• NSF 50 accuracy is based on Standards"

WHY USE A “STANDARD?”

•  Most Standards are for only one parameter and require dilution to your testing range"

•  Ready Snap 1P requires no dilution: just twist open, fill test cell with sample, and run test"

•  Can be used with most pool instruments and test methods"•  Ready Snap 1P are Plastic Ampoules that contain 10 ml of

POOL WATER Standard with known values and they can be used with most pool tests "

EXAMPLES OF STANDARDS

•  Turn on the Photometer and rinse out photometer cell three times with clean water"

•  Break open a Ready Snap by twisting the top 180°"

Using READY SNAP With a PHOTOMETER

STEP 1

•  Squeeze plastic ampoule to fill photometer cell to capacity (4mL)"

•  Discard this liquid sample followed with a quick shake of the meter to empty the photometer cell of the remaining water drops"

•  Squeeze plastic ampoule to fill the photometer cell again"

Using READY SNAP With a PHOTOMETER

STEP 2

•  Select the MENU for the test method procedure you want to verify (Calcium Hardness in this example) and run the test method as you would normally do the test"

Using READY SNAP With PHOTOMETER

STEP 3

"

*  Compare the Photometer Digital Display against the assigned value in the chart provided with Ready Snap Standard "

Using READY SNAP With a PHOTOMETER

STEP 4

•  If your value is within the acceptable range, you are operating the photometer correctly for the Calcium test method"

•  If your value is borderline, review that you are doing the test properly "

Using READY SNAP With a PHOTOMETER

STEP 5

Parameter TestMenuItem

DesiredValue

AcceptableRange

BorderlineRange

AL1 Total Alkalinity 82 ppm 70-94 60-104PH2 pH 7.6 pH 7.4-7.8 7.3-7.9 PO4 Phosphate 2.00 ppm 1.70-2.30 1.60-2.40CA5 Calcium as CaCO3 179 ppm 139-219 124-234CH6 Chloride as NaCl* 700 ppm 450-950 350-1050CY7 Cyanuric Acid 47.0 ppm 40.0-54.0 38.0-56.0CU8 Copper as Cu+2 0.19 ppm 0.15-0.23 0.13-0.25TDS Total Dissolved Solids 480 ppm 440-520 420-540 (504µS) as NaCl

R091213

Assigned Value Chart for READY SNAP™ 1P (lot 4813) Solution:

56;,!�=HS\LZ�YLÅLJ[�J\YYLU[�JVUJLU[YH[PVUZ�HZ�MV\UK�H[�[PTL�VM�THU\MHJ[\YL�*Chloride value uses the 1:20 dilution procedure in your Micro 10 manual on page 11 (CH6), beginning at step 1.0M�`V\�Y\U�[OL�9LHK`�:UHW��7�ZVS\[PVU�^P[OV\[�KPS\[PVU��[OL�TL[LY�^PSS�TVZ[�SPRLS`�YLHK�¸/0¹�

• Total Alkalinity • pH • Calcium Hardness • Copper

• Cyanuric Acid • Phosphate • Salt

USE READY SNAP STANDARD FOR VERIFYING THESE TESTS:

•  Circulate pool water before collecting sample, or manually stir water in sample area"

•  Rinse sample cell/vial two or three times with pool water before sampling"

•  Sample water 18 inches below surface (most important for Chlorine, Bromine, and Cyanuric Acid testing)"

TESTING Best Practices

•  Do not collect water sample near return lines"

•  Note the temperature of water to be tested (Very cold or very hot water can effect test results)"

•  Read test instructions for procedure how to run test with very cold or very hot water "

TESTING Best Practices

•  Perform tests as soon as possible after collecting sample (immediate testing is required for accurate Free Chlorine results)"

•  If collecting samples for later testing, handle carefully to avoid contamination, fill bottle to capacity, & seal sample bottle tightly "

TESTING Best Practices

•  Pay attention to expiration dates on test products"

•  Keep test reagent containers tightly capped and store in a cool, dark place when not using. "

•  Don't swap/mix the caps on reagent bottles to avoid chemical cross contamination"

TESTING Best Practices

• Where required, measure volume of water sample to be tested (Measure the bottom of sample meniscus, not the top at fill mark)"

• Don't interchange sample vials or cells"

• Follow manufacturer’s test directions carefully"

TESTING Best Practices

• Add liquid reagents carefully – make sure the correct number of drops are added to sample and drops are equal and full-sized"

• Mix reagents with test samples thoroughly"

TESTING Best Practices

• Record results and maintain those records for each pool or spa"

• Never dispose of tested samples/reagents in the pool"

• Rinse sample test vials and cells immediately after testing"

TESTING Best Practices

BALANCED WATER

•  Healthy Water = Balanced Water"•  For balanced water 6 parameters to consider and they

are used to calculate (Langelier) Saturation Index "1)  pH"2)  Total Alkalinity"3)  Calcium Hardness"4)  Total Dissolved Solids (TDS)"5)  Temperature"6)  Cyanuric Acid (CY)" "

•  Balanced Water is water that will neither scale nor corrode pool or spa surfaces and/or equipment

•  Corrosion is the dissolving or wearing-away of pool wall, pipes or equipment (SI value below 0.2)

•  Scale is the white deposit or precipitate that builds up on fixtures, surfaces, & equipment (SI value above 0.2)

•  Balanced water is non-irritating to eyes & skin of bathers, & allows sanitizer to work effectively (SI is perfect when 0 but OK best between -0.2 to +0.2)

BALANCED WATER

BALANCED WATER

Amazon price - $13.89

•  Protects bathers health – prevent transmission of infectious disease, prevent skin irritation, respiratory problems, eye irritation; etc"

•  Protects Pool or Spa surfaces & Equipment from corrosion and/or scale-formation, & discoloration"

•  Minimizes potential Health hazards from disinfection by-products (combined chlorine is especially a problem for indoor pools/spas)"

•  Maintains compliance with Health Dept regulations"" “Majority of pool problems are caused by poor water quality”""

BALANCED WATER

CYANURIC ACID (CY)

•  Used since 1956 in outdoor pools to protect chlorine from the Sun’s ultraviolet rays (Degradation)"

•  CY controls stability of the chlorine in the water but increases the amount of chlorine needed to maintain proper chlorine balance in pools"

•  CY buffers the pH against downward changes"•  Contributes to the overall Alkalinity level"•  Very important pool water parameter"

CYANURIC ACID (CY) and 10x RULE

Effectiveness of chlorine protection to keep pool clean and algae free is influenced by the CY concentration RATIO to Free Chlorine concentration"

•  Ratio of 8 to10 times is suggested to be best for clean pools so for convenience I use 10 times (10X RULE)"

•  When the CY level is 40 PPM then keep Free Chlorine level at 4.0 PPM (10X RULE)"

•  So if your pool has 100 PPM CY then technically you should have 10 PPM Chlorine (10X RULE)

CYANURIC ACID (CY)

•  CY forms weak reversible complex with Free Chlorine •  CY does not affect Tests for Free Chlorine (FC) •  CY/FC complex is affected by pH and concentration of FC and

CY •  CY/FC Complex ties up as much as 95% of the Free Chlorine.

So if your pool water test reads 4.0 PPM FC then your complex free chlorine level is about 0.2 PPM

•  As little as 0.01 to 0.05 PPM Free Chlorine is needed to keep pool clean according to CDC and World Health

CYANURIC ACID (CY)

•  Effective concentration is 10 times the Free Chlorine concentration (10X RULE)"

•  Amount recommended to stabilize Free CL"" 10 ppm CY - 1.0 ppm Free CL !! 20 ppm CY - 2.0 ppm Free CL!

30 ppm CY - 3.0 ppm Free CL! 40 ppm CY - 4.0 ppm Free CL !!50 ppm CY - 5.0 ppm Free CL!""

CYANURIC ACID (CY)

•  If CY is NOT used in an outdoor pool anticipate 75% Free Chlorine degradation every 60 minutes on a sunny day "

•  Makes good economic sense to use CY for Free Chlorine protection – less electricity for chlorine salt Cell "

•  So with a Free Chlorine of 3.0 ppm in the pool then a good level of CY is 20 to 30 ppm"

•  CDC has been recommending a CY level below 60 PPM "•  As CY increases, SI decreases so pool water becomes more

CORROSIVE "

CY AND TA

"•  Cyanuric Acid (CY) elevates theTotal Alkalinity (TA) in the

pool and is influenced by the pH in the water as follows" Examples: !CY of 40PPM with 7.0 pH elevates TA by 9 ppm !CY of 40PPM with 8.0 pH elevates TA by 14 ppm!•  So If you keep CY levels at or below 40 ppm the TA effect

averages about 10 ppm and at this level of CY you can ignore CY influence on TA. "

•  This is one more reason to keep CY below 40 PPM"

My CYANURIC ACID (CY) guidelines

•  Keep Cyanuric acid between 20 to 50 ppm"•  Levels above 50 ppm reduce chlorine effectiveness"•  Health Departments will close commercial pools above

100 ppm (Florida limit is 60 ppm) "•  When your CY levels are higher; then elevate the Free

Chlorine level (using 10X RULE) "•  To reduce CY levels, partially drain pool and refill "•  Keep track of CY levels regularly if you use Dichlor or

Trichlor in your service of pools "

VARIATIONS IN CY LEVELS

CY levels at the bottom, mid- and surface-levels at the deep end of one Olympic-sized pool with poor water circulation were found to vary: "

• Bottom – 100 ppm (12 feet)!• Mid-level – 50 ppm !• Pool surface – 20 ppm!

• Use a Photometer to get the most consistent test results for Cyanuric Acid ""

KEEP TRACK OF CYANURIC ACID LEVELS WITH BEST TEST

TOTAL ALKALINITY (AL)"•  AL is a measure of how much acid can be added

to a liquid without causing a significant change in pH (ability of water to resist a change in pH “Buffering capacity”)

•  Water with AL of 80 to 120 PPM will resist wide & rapid fluctuations in pH (called pH bounce)

•  AL is the bicarbonates, carbonates, & hydroxides in water

•  Proper AL stabilizes pH

TOTAL ALKALINITY (AL)"

•  If AL is low, pH will be especially affected by the Salt Pool Generator "

•  If AL is high, pH will be difficult to adjust and water will scale "•  Total Alkalinity is key to pH water balance"•  Recommended that it should be adjusted FIRST, before pH"•  Addition of acid or alkaline to adjust pool or spa Alkalinity will

change pH, and vice versa"

Low Alkalinity (below 80PPM) can cause:"•  Wide and rapid pH fluctuations "•  Corrosion of pool or spa and equipment "•  Skin / Eye Irritation "•  Cloudy water"•  Adding acid like Muriatic Acid will lower pH & Alkalinity"

TOTAL ALKALINITY (AL)"

•  If you add supplemental Chlorine products anticipate their different pHs, and anticipate Alkalinity effect"

•  Ideal level is 80-100 ppm with CHLORINE sanitizers such as Sodium, Calcium, or Lithium Hypochlorite"

•  Ideal level is 100-120 ppm with CHLORINE sanitizers such as Dichlor, Trichlor, Bromine, or Chlorine Gas"

•  Salt Pools need 80 to 120 PPM" NOTE: Parts per million (ppm) is equivalent to milligrams per liter (mg/L).

TOTAL ALKALINITY (AL)"

ORDER OF pH and AL ADJUSTMENTS

•  pH is most important factor"•  Affects all other chemical / balance

parameters"•  Determines acidity of water "•  Measured on a scale from 0-14 "•  pH 7 is neutral"•  Below 7 is acidic (e.g. lemon juice and

coke)"•  Above 7 is basic or alkaline (e.g. baking

soda and concrete) "

pH"

•  pH in the ideal range will be comfortable for human eye at 7.5"

•  Pool water pH is acceptable from 7.2 - 7.8 "•  Ideal pH range is 7.4 - 7.6 "•  pH levels should be tested DAILY!"•  High pH reduces Chlorine’s effectiveness"

pH"

pH "

CALCIUM HARDNESS (CA)"

•  Defined as the amount of Calcium Salts in water (reported as Calcium Carbonate or CaCO3) "

•  The term Calcium Hardness is used because hardness in tap water is mainly due to Calcium"

•  Magnesium, barium & sulfate also contribute to Hardness"•  Make-up water used to fill pool will vary in its calcium content

depending on region of country / city or well water"•  Ideal range is 200-400 PPM as CaCO3 in Salt Pools"•  Maximum of 1000 PPM is listed for non-salt pools?"

CALCIUM HARDNESS (CA)"

CALCIUM HARDNESS (CA)"

•  CA levels should be tested Monthly "•  Pool & spa water must have a certain amount of Calcium "•  Calcium Hardness, when outside optimal range, can

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 water hardness allows corrosion or pitting of calcium

rich surfaces such as concrete, plaster, & grout "

TOTAL DISSOLVED SOLIDS(TDS)"

•  TDS is the total of all dissolved material in water "•  TDS value is contributed and influenced by ions of

calcium, magnesium, sulfate, chloride, sodium, potassium, phosphate, nitrate, all ions; Alkalinity; Cyanuric Acid; and other chemicals present in water"

•  If it is dissolved in the water, it is part of TDS"

TOTAL DISSOLVED SOLIDS(TDS)"

TOTAL DISSOLVED SOLIDS(TDS)"

High TDS levels (above1500 ppm the initial TDS value) increase these undesirable events:"•  Increases algae growth despite adequate sanitizer"•  Corrosion despite water being otherwise balanced"•  Cloudy water despite adequate filtration"•  Eye and skin irritation"•  Deposits on pool wall"•  Salt pool TDS just add salt concentration: so 3500 PPM

Sodium Chloride will add about 3500TDS"

TOTAL DISSOLVED SOLIDSin Salt Pools "

•  TDS will increase in a salt pool over time"• Why? - chemicals are added, dirt and debris

blow or wash into pool "•  water evaporation from pool"•  If TDS exceeds 1500 ppm over salt 3500TDS

(5000PPM) monitor TDS, clarity, and SI "•  TDS in Salt pools technically can work even at

8000 ppm but requires monitoring effort to keep track especially of SI "

TESTING TDS

•  TDS levels should be tested MONTHLY using "1.  Digital Conductivity meter ($20 - $900)

(can do thousands of tests)"2.  Test strips ($0.30 to $0.50 per test)

"•  Maximum TDS is 1500 ppm over start-up TDS"•  Some professionals find 5000 ppm TDS levels in pool water

acceptable"

TEMPERATURE"

• Temperature is a water balance factor but difficult to control"

• Pool water is normally 78 - 82◦ F. "• Spa water is normally 96 - 104◦ F"• Test with digital or IR thermometer"

•  If pH goes up then Calcium Hardness and Alkalinity has to be kept at lower end (200 for CA & 80 for AL)

• Danger signs – pH above 7.8 and TA above 120

SI and RELATIONSHIP OF BALANCED WATER

SI (LSI)

SANITIZER AND DISINFECTANTS"

•  A disinfectant kills disease-causing organisms"•  A sanitizer kills all microorganisms with impunity,

(USEPA 99.9% effective) i.e. , chlorine"•  Oxidation refers to the “chemical reaction” that organic

contaminants or waste products undergo"•  The pool environment is constantly exposed to new

contaminants, two important considerations:"1.  Sanitize water to kill microorganisms"2.  Oxidize organic contaminants"

CHLORINE"

•  Chlorine is the most popular worldwide sanitizer, disinfectant, algae killer and oxidizer"

•  Chlorine is inexpensive and safely generated by Salt Systems "

•  Chlorine doubles as a sanitizer and oxidizer in a pool or a spa"•  Chlorine is most effective under certain conditions –

The pH is most important factor and must be in optimal range for chlorine to be effective"

CHLORINE

•  Effective against a broad range of microorganisms "•  Over 79,000 tons are used in the United States and

Canada to treat water yearly"•  Monitoring chlorine concentrations is very important "•  Used in pools to protect bathers health, water clarity and

equipment"•  Inactivation of pathogens depends on contact time"•  In the United States, Health Departments require

all public pools to be routinely tested for chlorine"

GERM INACTIVATION TIME IN 1 ppm CHLORINATED WATER"

GERM" INACTIVATION TIME"E. Coli O157:H7 Bacterium"

Less than 1 minute"

Hepatitis AVirus"

About 16 minutes"

Giardia Parasite"

About 45 minutes"

CryptosporidiumParasite"

About 15300 minutes(10.6 days)"

pH 7.5, 77 F"

CHLORINE SOURCES Salt Systems generate HOCl -------or NaOCl equivalent "

Chemical Name"

Chemical Formula"

Form" % Chlorine"

Chlorine Gas"

Cl2 " Gas" 100%"

CalciumHypochlorite"

Ca(OCl)2 " Solid" 65-70%"

SodiumHypochlorite"

NaOCl " Liquid" ~12% "

ABOUT CHLORINE SOURCES "

* Despite their chemical and physical differences, they form hypochlorous acid, or as more commonly known in the pool industry - Chlorine"

* This change occurs when added to water"* Hypochlorous acid (HOCl) is the effective

disinfecting agent and this is what your Salt Generator makes "

CHLORINE CHEMSTRY"

• The sum of Hypochlorous acid (HOCI) and Hypochlorite ion (OCI ¯) is called free chlorine, and the chemical equation or relationship is:"

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 especiallywhen pH level is above 7 which causesHypochlorous acid to form Hypochlorite ion "

HYPOCHLOROUS ACID REACTIONS"

•  Hypochlorite ion is less than one third as effective as a disinfectant as Hypochlorous acid"

•  The next slide shows the relationship between pH versus chlorine species (Hypochlorous acid and Hypochlorite ion) "

pH VERSUS CHLORINE SPECIES

CHLORINE REACTION"

•  The SECOND REACTION is a series of chlorine reactions that occur with ammonia (NH3) and organic nitrogen compounds like proteins and amino acids in the pool to form chloramines"

•  Chloramines are less effective disinfectants "

•  Active chlorine can be transferred from inorganic chloramine to amine (organic) containing compounds "

BREAKPOINT CHLORINATION

111

•  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” or “Super-Chlorination”"

•  Shock is required less frequently in Salt pools and depends on a variety of considerations BECAUSE??"

TOTAL CHLORINE

•  Total chlorine is the sum of free chlorine and combined chlorine"

•  Free chlorine and total chlorine can be monitored by automated equipment and confirmed by poolside testing for swimmer protection"

Total Chlorine = Free Chlorine + Combined Chlorine"

•  DPD methods have become preferred for chlorine measurement "

•  DPD methods determine concentration by measuring intensity of color formed when chlorine reacts with DPD "

•  DPD-FAS Titration method determines chlorine by measuring amount of FAS Titrant needed to bleach out DPD-chlorine color formed "

•  State health departments accept DPD tests because they are quick, enjoy wide acceptance & EPA approved"

DPD CHLORINE TESTING"

•  Combined chlorine = TC - FC"

•  Free chlorine = 2.58 ppm (FC)"

•  Total chlorine = 2.89 ppm (TC)"

•  Combined chlorine = 2.89 – 2.58 = 0.31 ppmCombined 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 above the 2.89 ppm!

TOTAL CHLORINE (TC) = FREE CHLORINE (FC) + COMBINED

CHLORINE

OTHER COMMON WATER QUALITY

PARAMETERS AND TREATMENT SOLUTIONS

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 "

OZONE

•  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

•  Another word for cloudiness"

•  Caused by several factors: "

1.  Body-waste contamination"

2.  Non-organic suspended solids"

3.  Algae"

4.  Chemical imbalance (high alkalinity, high calcium)"

•  Turbidity is most commonly measured with a “turbidometric” meter – and is very accurate"

•  Can be tested with a photometer (less accurate)"

TURBIDITY

•  Pride in your work •  Customers expect it •  Health Departments require it •  Liability issues are bad for

business

STRIVE FOR BEST RESULTS

Questions?

Ivars Jaunakais – Chief Analytical ChemistIvars@sensafe.com www.sensafe.com

DOWNLOAD THIS PRESENTATION: http://www.slideshare.net/sensafe"

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/ "•  Internet: NSF http://www.NSF.ORG"