understanding pool & spa water testing

UNDERSTANDING POOL & UNDERSTANDING POOL & SPA WATER TESTINGSPA WATER TESTING

By Ivars JaunakaisBy Ivars JaunakaisOrlando Pool and Spa Show • February, 2010Orlando Pool and Spa Show • February, 2010

R 021710

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?

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

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

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

TESTING IS IMPORTANT

Pools and Spas must be maintained in a conscientious way

Primarily for thesafety of bathers

Liability Good testing practices

reaps financial rewards

TESTING TOOLS

Test strips Colorimeters Test reagents

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

Over 12 million pools and 5 million spa in theUnited States all require maintenance

THE GOALis 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

3 THINGS TO MAINTAIN A HEALTHY POOL OR SPA

Circulation Filtration Routine

Cleaningand Maintenance

STATE OF FLORIDA64E-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

(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.


The following parameters shall be adhered to for pool water treatment:

pH – 7.2 to 7.8.


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.


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 %

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.


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.


CHLORINE VS ORP READING

Cyanuric acid

1. 100 mg/L maximum in pools

2. 40 mg/L in spa poolsNOTE: Expect this level to be lower in the future


Quaternary ammonium

5 mg/L maximum in pools or spas


Copper –

1 mg/L maximum in pools or spas


Silver –

0.1 mg/L maximum in pools or spas


The pool recirculation system must be operated

The pool water level must be maintained All equipment and appurtenances should

be in good repair


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


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


The following test kits shall be provided if the corresponding chemicals are used:

1) Cyanuric acid

2) Sodium chloride

3) Quaternary ammonium

4) Copper


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.


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.


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

DEPARTMENT OF HEALTH MONTHLY SWIMMING POOL REPORT

STATE PERMIT # DATE NAME OF POOL ADDRESS Days of month

Chlorine residual

pH

Filter Gauge Reading

POOL VOLUME IN GALLONS ___________________

9 AM 1 PM 4 PM 9 AM 1 PM 4 PM Vacuum

in/Hg

Pressure: Influent

PSI

Pressure: Effluent

PSI

Flow GPM

Pool Vacuumed

No. Patrons

Remarks Enter items such as: Total alkalinity, hardness,

cyanuric acid, equipment breakdown, excessive pool water loss, filter backwash, water clarity

1 2 3 4 5 6 7 8 9

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31

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


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/


DISINFECTION OF POOLAFTER FECAL ACCIDENT

OTHER BODY FLUIDS Vomit

1. Noroviruses germ hazard

2. Respond to the vomit accident as you would respond to a formed fecal accident, using CDC's recommendations

Blood

1. Germs don’t spread in properly chlorinated pool

2. There is no public health reason to recommend closing the pool after a blood spill

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

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.

WATER BALANCE5 FACTORS THAT AFFECT IT

1. pH (PH)

2. Total Alkalinity (AL)

3. Calcium Hardness (CA)

4. Total Dissolved Solids (TDS)

5. Temperature

pH, AL, or CA is high, the water will deposit scale

pH, AL, or CA is low, the water will corrode

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)

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

pH VERSUS CHLORINE SPECIES

Percent HOCl and OCl- vs. pH

0

10

20

30

40

50

60

70

80

90

100

6.0 6.5 7.0 7.5 8.0 8.5

pH

Per

cen

t H

OC

l an

d O

Cl-

HOCl

OCl-

HOCl

Hypochlorous Acid

OCl-

Hypochlorite Ion

WATER BALANCE - pH

WATER BALANCE - pH What causes pH to go up

Adding Alkali like Soda Ash Alkali Sanitizers like Sodium

Hypochlorite

TESTING pH Colorimetric visual tests

1. liquid test (using Phenol Red)

2. tablet test

3. test strips

Colorimetric test meter with pH indicator reagent

pH meter with electrode probe

1. Must be calibrated properly

2. Probe end is made of glass

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

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

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

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

TESTING TOTAL ALKALINITY (AL)

Colorimetric visual tests

1. liquid test (titration)

2. tablet test

3. test strips Colorimetric test meter with AL reagent

ORDER OF pH & AL ADJUSTMENTS

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


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.

TESTING CALCIUM HARDNESS (CA)



2. tablet test

3. test strips Colorimetric test meter with CA reagent

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.


TDS levels need to be known because high levels increase undesirable events:

1. Algae growth despite adequate sanitizer

2. Corrosion despite the water being balanced

3. Cloudy water despite adequate filtration

4. Eye and skin irritation

5. Deposits on the pool wall


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)


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

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

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

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


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


Mr. Langelier assigned a value to each of these Mr. Langelier assigned a value to each of these factors and developed an equation.factors and developed an equation.

SI = pH + TF (Temperature) + CF (Calcium Hardness) + AF (Total Alkalinity) – 12.1 (TDS)


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)


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 PPM12.2 if from 1000-2000 PPM12.3 if TDS is above 2000 PPM

pH is used without alteration

LANGELIER SATURATION INDEX (SI) TABLE

Temperature °F = TF

Calcium Hardness = CF

Total Alkalinity = AF

32° = 0 5 = 0.3 5 = 0.7 37° = 0.1 25 = 1.0 25 = 1.4 46° = 0.2 50 = 1.3 50 = 1.7 53° = 0.3 75 = 1.5 75 = 1.9 60° = 0.4 100 = 1.6 100 = 2.0 66° = 0.5 150 = 1.8 150 = 2.2 76° = 0.6 200 = 1.9 200 = 2.3 84° = 0.7 300 = 2.1 300 = 2.5 94° = 0.8 400 = 2.2 400 = 2.6 105° = 0.9 800 = 2.5 800 = 2.9 128° = 1.0 1000 = 2.6 1000 = 3.0

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)


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!

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)

SANITIZER AND DISINFECTANTS The pool environment is exposed to constantly introduced

things

Two important things must be done:

1. Sanitize the water to kill microorganisms

2. 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

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

CHLORINE

Effective against a broad range of microorganisms Chlorine first used in 1908 for public healthMore 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

equipmentSeveral pathogens can be transmitted in waterInactivation of pathogens depends on contact timePublic health requires pool water testing for

Hypochlorous acid or free chlorine residual concentration

7878

GERM INACTIVATION TIME IN 1 PPM CHLORINATED WATER

GERM INACTIVATION TIME

E. Coli O157:H7Bacterium

Less than 1 minute

Hepatitis AVirus

About 16 minutes

GiardiaParasite

About 45 minutes

CryptosporidiumParasite

About 15300 minutes(10.6 days)

pH 7.5, 77 °F

BACTERIA REGROWTH

RISKOF

ILLNESS

RISK OF ILLNESS

8282

SOURCES OF CHLORINE

ChemicalName

ChemicalFormula

Form % Chlorine

Chlorine Gas

Cl2 Gas 100%

CalciumHypochlorite

Ca(OCl)2 Solid 65-70%

SodiumHypochlorite

NaOCl Liquid ~12%

TYPICAL DEGRADATION RATE OF SODIUM HYPOCHLORITE

8484

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

8585

CHLORINE CHEMSTRY

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

8686

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 causesHypochlorous 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)

pH VERSUS CHLORINE SPECIES

Percent HOCl and OCl- vs. pH

0

10

20

30

40

50

60

70

80

90

100

6.0 6.5 7.0 7.5 8.0 8.5

pH

Per

cen

t H

OC

l an

d O

Cl-

HOCl

OCl-

HOCl

Hypochlorous Acid

OCl-

Hypochlorite Ion

8888

CHLORINE REACTION

Second chlorine reaction is with ammonia (NH3) 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

8989

COMBINED CHLORINE EQUATIONS

The sum of the chloramine species is called combined chlorine, and chemically created in the pool as follows:

9090

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

EUROPEAN DIN REGULATION The German DIN regulation requires pools be

drained:

1. Once a month or

2. ¼ every week or

3. 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

9292

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

9393

TO ACHIEVE GOODTEST 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

9494

US EPA ACCEPTED TEST METHODS(ACCEPTED BY FLORIDA HEALTH DEPARTMENT)

DPD-FAS Titrimetric Method

DPD Colorimetric Meter Method

DPD Colorimetric Visual Method

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)

9696

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

9797

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

9898

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 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

9999

Free Chlorine, reference method versus test method

y = 1.0268x + 0.0126

R2 = 0.9998

0.00

2.00

4.00

6.00

8.00

10.00

0.00 2.00 4.00 6.00 8.00 10.00

reference method (ppm)

tes

t m

eth

od

(p

pm

)

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

COLORIMETER + LIQUID DPD POOLSIDE TESTING PROCEDURE

1. Rinse out photocell 3 times with pool water

2. Fill to 10 ml line with pool water sample

3. Cap cell, wipe cell wall

4. Place cell in colorimeter and zero meter

5. remove cell and uncap

6. add five drops of buffer DPD-1 solution

7. add five drops of indicator DPD-2 solution

8. cap cell and mix for a few seconds

9. wipe cell wall

10. place in colorimeter and read chlorine result

COLORIMETER + DPD-1 POWDER PILLOW POOLSIDE TESTING PROCEDURE

1. Rinse out photocell 3 times with pool water sample




5. remove cell and uncap

6. Tear open powder pillow and add DPD-1

7. Cap cell and mix for 20 seconds

8. Wipe cell wall

9. Place in colorimeter and read chlorine result

COLORIMETER + DPD-1 TABLET POOLSIDE TESTING PROCEDURE

1. Rinse out photocell 3 times with pool water sample

2. Fill cell to 10 ml line with pool water sample



5. Remove cell, uncap cell,

6. Pour out water except for a few drops

7. Add DPD-1 Tablet and crush with tablet crusher

8. Add pool water back to 10 ml line

9. Cap cell and mix for about 20 seconds

10. Wipe cell wall

11. Place in colorimeter and read chlorine result

COLORIMETER + DPD-1 TEST STRIP POOLSIDE TESTING PROCEDURE

1. Rinse out photocell 3 times with pool water

2. Fill meter cell to capacity with pool water

3. Turn meter on and Zero

4. Dip DPD-1 Test Strip into sample for 20 seconds with back and forth motion (Press “READ” button that begins countdown timer)

5. Read chlorine result

NOTE: This is a recent development in DPD testing

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

Step 3

Turn meter on and Zero


Step 4

Dip DPD-1 Test Strip into sample for 20 seconds with back and forth motion (Press “READ” button that begins countdown timer)


Step 5

Read chlorine result

Free Chlorine = 1.58 ppm


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)


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


FAS DPD POOLSIDE TESTING PROCEDURE1. Rinse out cell 3 times with Pool water sample


3. Add five drops of buffer DPD-1 solution

4. add five drops of indicator DPD-2 solution (or one scoop of DPD Powder)

5. Swirl to mix for a few seconds

6. Add one drop of FAS reagent, swirl to mix and observe color

7. Add next drop of FAS Reagent, swirl to mix and observe color (Repeated for a total of 14 drops)

8. 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

SPA WATER CHEMISTRY

Spas differ from pools because: 1. They have a much smaller volume2. 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.

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

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 300030

= 33

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

BROMINECHEMISTRY

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

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)

BIGUANIDES (PHMB)

Biguanides are unique for the pool marketThe term refers to a disinfectant polymer

polyhexamethyline biguanicide (PHMB)It is an effective sanitizer but not an oxidizerHydrogen 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 kitPHMB 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

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

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:

1. Anode (positively-charged)

2. 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.


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


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)

SALT TEST KITS



2. tablet test

3. test strips Colorimetric test meter with SALT reagent

(typical testing requires a dilution step)

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 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

IONIZATION OFCOPPER 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

IONIZATION OFCOPPER 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

COPPERTESTING

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

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)

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.

IRON BECOMES AN ION

Fe Fe+2 (Ferrous) + 2 electrons

Fe Fe+3 (Ferric) + 3 electrons

Fe+2 + Cl2 FeCl2 (Ferrous Chloride)

2Fe+3 + Cl2 2Fe2Cl3 (Ferric Chloride)

4Fe+3 + 3O2 2Fe2O3 (Iron Oxide)

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

IRON REMOVAL

Chelating or Sequestering Agents work best

They prevent any iron coating on the pool walls

IRON TESTING


1.liquid test

2.tablet test

3.test strips Colorimetric test meter with FE and Reducing

Reagents

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.

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

PHOSPHATE BECOMES AN ION

P P+5 + 5 electrons 4P + 5O2 2P2O5

P2O5 + 3H2O 2H3PO4

(phosphoric acid) H3PO4 + H2O H3O+ + H2PO4

–

(dihydrogen phosphate) Ca(H2PO4)2 Calcium Dihydrogen Phosphate is

known as “Super Phosphate of Lime” and used as a fertilizer

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)

ANOTHER WAY TO CONTROL ALGAE GROWTH

In Florida, Catfish are used to eat the algae in abandoned pools

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

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 & 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

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)

PHOSPHATE TESTING


1.tablet test

2.test strips Colorimetric test meter with PO4 reagent

TURBIDITY

Another word for cloudiness

Caused by several factors:

1. Body-waste contamination

2. Non-organic suspended solids

3. Algae

4. Chemical imbalance

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

Can also be tested with a colorimeter (less accurate)

TEST METHODTurbidometric 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

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.

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.

COLORIMETIC TESTS

There are four basic colorimetic methods used in testing pool and spa water:

1. Colorimetric tests use a Colorimeter and reagent delivery device such as: liquid, powder, tablet, and test strip

2. Colorimetric visual using titration (counting drops)3. Colorimetric tests use a reagent delivery device

such as: liquid, powder, tablet, or test strip with a tube and a comparator color chart

4. Colorimetric visual test strips are used most commonly for testing these three parameters: Free Chlorine, pH, Alkalinity levels

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

TEST METHOD #1Colorimeter 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

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

TEST METHOD #3 Colorimetric reagent with color chart comparator Inexpensive reagents

Gives only minimum resolution

Reagents may have stability issues

Requires good visual judgment

TEST METHOD #4 Colorimetric visual test strips with color chart Quick and easy Inexpensive Suitable for screening Good shelf life Does not use DPD

TEST METHODSAND EQUIPMENTConsiderations 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)

TEST KITPERFORMANCE 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

TEST KITPERFORMANCE 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

TEST METHODSAND EQUIPMENTConsiderations 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

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

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

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:

1. Proper light

2. Do not wear sunglasses

3. Read the colors against an appropriate background

4. 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

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/

STRIVE FOR BEST RESULTS

Customer wants it State Health Department requires it. Liability for bad results

Any Questions? Ivars Jaunakais – Chief Analytical Chemist Ivars Jaunakais – Chief Analytical Chemist

[email protected] [email protected] www.sensafe.com

THANK YOU FOR YOUR ATTENTION!!

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