Proper Testing in Salt Water Pools

Proper Testing ProceduresProper Testing Procedures
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Salt Water PoolsSalt Water Pools
(The Importance of Accurate Results)
By Ivars Jaunakais
Thursday September 26, 2013
1:00 PM -1:45 PM / 2 CE Credit Hours

• History and benefits of salt pools
• The importance of balanced water
• Different and proper water testing methods and techniques
• What salt pool tests need to be done
• How to easily verify that you, the test method, and reagent is
giving you correct answers
TOPICS

SALT POOL HISTORY
• Developed in Australia back in 1965
• 80% of all Australian pools use salt
• Introduced in USA in 1980
• Popularity in USA finally caught on in the last
10 years as technology improved

HISTORY
• In 2007 nearly 75% of American new pool installations
were salt pools
• An increase of 15% from 2002
• Currently over 1.6 million pools in the United States
use salt

BENEFITS
• Water is gentler on skin, eyes, nose and hair
• Simple and convenient maintenance
• Environmentally friendlier (less chemicals?)
• Less expensive to operate in the long run
• Less prone to algae problems

• Adequate generation of
Chlorine by Salt System
• Regular testing of pool water
• Weekly Cleaning and
Maintenance
• Adequate circulation time
• Quality filtration
• Know what’s in the make-up
water to anticipate problems
MAINTAINING A SALT POOL

• Proper maintenance of salt pools
begins with water testing
• Primarily for the safety of bathers
• Avoids Liability issues
• Accurate and routine testing results in
less problems
• Testing is required to keep salt pools
balanced
• Chlorine testing is required to know if
Salt System is adjusted properly
TESTING IS VITAL

• Weekly testing of pH and chlorine
• Monthly testing during the season for
total alkalinity, calcium hardness, metals,
and cyanuric acid
• Monthly testing of salt levels need to
match the proper level as specified by the
chlorine generator manufacturer
TESTING IS VITAL

• Happy customers
• Accurate test results
support correct
maintenance, saving you
and your customers
money
• Increased business
SERVICE GOALS

• pH levels rise due to constant electrolysis (if problem
continues consider Borate Buffer option)
• Requires more muriatic acid to keep pH OK
• This lowers total alkalinity levels
• Monitor Cyanuric Acid levels
• Monitor Salt levels
• Corrosion of metal parts
• Higher electricity use
SALT POOL ISSUES

• Pool salt levels
• Stabilizer levels
• Control box settings
• Pool circulation time settings
COMMON ISSUES

• Poolside testing often performed in
undesirable environmental
conditions
• Temperature, humidity, sunlight,
wind, and rain affect results
• Distractions including poolside
activity and noise
POOLSIDE TESTING
CHALLENGES

• Cost per test (varies $0.02 to $0.30 up to $10)
• Time to run test (time = money)
• Ease of use
• Portability and stability of tests
• Compliance testing requirements if testing public or
commercial pools and spas (meets State Health
Department approval)
• Test gives good results with a test Standard
TESTING CONSIDERATIONS

• Be acceptable or compliant
(i.e., Chlorine test uses DPD indicator)
• Use tests that don’t challenge your patience
• Not be technically difficult
• Use reagents and equipment that are safe, reliable,
and stable
• Have good resolution (so precision is reliable)
• Be accurate (answer is correct)
TESTING SHOULD…

• Colorimeters (Photometers) and reagents
• Titration or drop reagents
• Comparator test
• Test Strips
COMMON TESTING TOOLS

Four colorimetric methods:
1) Digital Photometer – uses different reagents
(liquid, powder, tablet, or reagent strip)
2) Colorimetric titration - counting drops and matching color
using liquid and powder reagents
3) Comparator color test – uses liquid, powder, tablet, or
reagent strip with a test tube or comparator color chart
scale
4) Test strips - visual matching to a color chart scale
COLORIMETIC TESTS

• Uses colorimetric or precipitation
chemistries and the color
(or precipitate) is measured by a
digital instrument that measures
light transmission through sample
• Concentration is determined by the amount of light that is
transmitted through the reacted pool water sample
• Chlorine has 0.01PPM resolution; 0.03 PPM accuracy
• Hardness has 1PPM resolution; 10 to 20 PPM accuracy
TESTING TOOL #1
Photometer and Reagent
(Most accurate method)

RESOLUTION EFFECTS ACCURACY!
Resolution 1 ppm Resolution 0.1 ppm

• Colorimetric chemistry that uses visual
color change for testing concentration
• End point color change can be difficult to gage
• Accurate counting of drops is required
• Test is dependent on technique
(swirling is required )
• Math required (drops are multiplied by
concentration factor)
• Chlorine has 0.2 PPM (or 0.5PPM) resolution
and expect 0.6PPM (or 1.5PPM) accuracy
• Hardness has 20PPM resolution; 60 PPM
accuracy
TESTING TOOL #2
Colorimetric (visual) titration
Commonly used FAS/DPD method

• Fast and inexpensive
• Minimum resolution & accuracy
• Liquid reagents have stability issues
• Requires good visual judgment
• Chlorine has 1PPM resolution and 3
PPM accuracy at lower levels
• pH has 0.3 resolution; 0.5 accuracy
TESTING TOOL #3
COLOR COMPARATOR

• Fast and inexpensive
• Suitable for screening
• Good shelf life
• pH resolution is 0.3 and
accuracy is 0.5
• Chlorine resolution is 1 PPM
or greater and accuracy is 3 PPM
• Available for most parameters
TESTING TOOL #4
Test strips

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

• 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 careful attention to
expiration dates on
reagents and test strips
• Keep reagent containers tightly
capped and store in a cool, dark
place when posiible.
• 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

Match visual test results under
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
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

∗ When using a photometer, verify your
results using a Pool Water Standard to
verify photometer, reagents, and operator
∗ Pool Water Standards can also be used for
verifying titration and comparator reagents
TESTING
Best Practices

Average ACCURACY you can expect

IDEAL LEVELS for Salt Pools
CHEMICAL IDEAL LEVELS
Salt 2700 to 3400 ppm
Free Chlorine 1.0 to 3.0 ppm
Cyanuric Acid 60 to 80 ppm
Total Alkalinity 80 to 120 ppm
Calcium Hardness 200 to 400 ppm
Metals (Copper?) 0 ppm
Saturation Index -0.2 to +0.2 (non-salt pools -0.05 to +0.05)
Nitrates at 0 PPM

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

• Chemicals found in make-up water, when treated by the
municipal water treatment plant. Including disinfection by-
products: lime, alkalis, phosphates and ammonia that forms
monochloramines (combined chlorine compounds) in some
chlorine treated systems
• Metals in make-up water is frequently found because pipes
corrode as water flows through them
• Chemicals used to treat pool water - pH correction
chemicals, sanitizers, oxidizers, stabilizer, chemicals for
treating algae, mold, etc.
CHEMICAL SOURCES
IN POOL WATER

• Bather sweat, urine, dirt, lotions, sunscreen, cosmetics, soap
residues, deodorant, hair spray, etc.
• Environmental items - debris, dirt, leaves , vegetation, etc.,
also contribute chemicals
• Disinfection by-products - trihalomethanes, haloacetic acids,
chlorate, nitrogen trichloride, etc.
• Rain water (can dilute your balanced water)
OTHER THINGS IN
POOL 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)

Proper Testing in Salt Water Pools

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

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 chemicals = less money on Chlorine
• So with a Free Chlorine of 3.0 ppm in the pool then a good
level of CY is 20 to 30 ppm
• NEW recommendations by CDC is to limit the CY level to a
maximum of 60 PPM
• As CY increases, SI decreases so pool water becomes more
corrosive

CY AND TA
• Cyanuric Acid (CY) effects Total Alkalinity (TA) in the pool
• CY elevates TA and is influenced by the pH
Examples:
CY of 40PPM with 7.0 pH elevates TA by 8.8 ppm
CY of 40PPM with 8.0 pH elevates TA by 14.4ppm
• So If you keep CY levels at or below 40 ppm the TA effect
averages about about 10 ppm and at this point you can
ignore CY influence on TA.
• This is one more reason to keep CY below 40 PPM

CYANURIC ACID
IN THE U.S.
One study 20 Years ago reported:
• Average concentration – 76 ppm
• Maximum concentration – 406 ppm
• Another more recent study reported 25% (122 of 486) of
private pools had more than 100 ppm
• CY is allowed for public pools in every State except
New York
• CDC recommends CY levels below 60PPM because
higher levels have potential PROBLEMS

My CYANURIC ACID (CY) guidelines
• The optimal level for cyanuric acid is 20 - 50 ppm
• Levels above 50 ppm reduce chlorine effectiveness
• Health Departments will close commercial pools above
100 ppm (Florida recommends 60 ppm)
• When using CY maintain Free Chlorine using 10X
RULE
• To reduce CY levels, partially drain pool and refill
• Test and keep track of CY levels regularly if you use
Dichlor or Trichlor in your service

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

• Photometric (1 ppm)
• Visual black dot comparator (over
20 ppm)
• Test Strip (over 50 ppm)
CYANURIC ACID
TEST METHODS (resolution)

• You need to use Photometric method
to get accurate test results for
Cyanuric Acid
• Very important when you want to keep
CY between 20 - 50 ppm
CYANURIC ACID
TESTING IN THE FUTURE

TOTAL ALKALINITY (AL)
• AL is a measure of how much acid can be added to
a liquid without causing a significant change in pH
• AL is the 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

• If AL is low, pH will be affected by anything introduced into
the pool
• If AL is high, pH will be difficult to adjust (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

• When 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
• Maximum must be below 160 PPM
NOTE: Parts per million (ppm) is equivalent to milligrams per liter (mg/L).

•Photometric (1 ppm)
•Titration (10 ppm)
•Test Strips (40 ppm)
TOTAL ALKAINITY

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 meter (0.01 or 0.1)
•Photometric (0.1)
•pH comparator (0.2)
•Test Strips (0.2 or 0.3)
pH Testing Methods (resolution)

CALCIUM HARDNESS (CA)
• Defined as the amount of Calcium Salts in water
(reported as Calcium Carbonate)
• Term Calcium Hardness used because hardness in tap water is
due to Calcium
• Magnesium, barium & sulfate can 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
• Maximum of 1000 PPM ?

CALCIUM HARDNESS (CA)
• CA levels should be tested regularly
• 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

•Photometric (1 PPM)
•Titration (20 PPM)
•Test Strips (over 50 PPM)
CALCIUM HARDNESS

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

(TDS)
High TDS levels ( over 1500 PPM) 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

in Salt Pools
• TDS will increase in a salt pool over time
• Why? - chemicals are added, dirt and debris
blow or wash
• water evaporation from pool
• If TDS exceeds 1500 ppm of initial level (like
5000PPM) monitor TDS, clarity, and SI
• TDS at even 8000 ppm can work but requires
effort to keep track 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

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, safe when used properly effective
• 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 A
Virus
About 16 minutes
Giardia
Parasite
About 45 minutes
Cryptosporidium
Parasite
About 15300 minutes
(10.6 days)pH 7.5, 77 F

CHLORINE SOURCESS
Salt Systems generate HOCl
-------or NaOCl
equivalent
Chemical
Name
Chemical
Formula
Form %
Chlorine
Chlorine
Gas
Cl2 Gas 100%
Calcium
Hypochlorite
Ca(OCl)2 Solid 65-70%
Sodium
Hypochlorite
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

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 especially
when pH level is above 7 which causes
Hypochlorous 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)

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
89
• 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

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

• DPD Photometric Digital Meter (0.01)
• DPD-FAS Titrimetric (0.2)
• DPD Colorimetric Comparator (1 or 2)
• TMB Test Strip (0.2 but only detects free
chlorine)
EPA ACCEPTED
CHLORINE TEST METHODS
(FREE AND TOTAL)

• 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
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

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
• Pool water will be regularly
refreshed with City make-up water
that may contain 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

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
• In high concentrations, salts will not cause cloudy water or
staining of the pool

KEEP Salt POOLS
PHOSPHATE FREE
• Test the water phosphate levels regularly
• Avoid lawn/garden run-off from entering the pool
• Remove leaves promptly
• Keep phosphate below 120 ppb (0.12PPM)
• Test the make-up water for phosphate (City water may
have as much as 1 PPM or 1000PPB phosphates)
• Preferred photometric test uses molybdate reaction with
phosphate in mild acid solution to form
molybdophosphoric acid or heteropoly blue complex

PHOSPHATE TESTING
(resolution)
• Digital Photometric with reagent 0.01 PPM (or 10 PPB)
resolution
• Test Strip with Comparator 0.1 PPM (or 100 PPB)
resolution
• Ideally keep level below 0.1PPM or 100 PPB
• If Chlorine is maintained above 4PPM and CY below
60PPM pool can tolerate 0.5PPM (500PPM) phosphate
without algae problem.

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
• 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 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
• 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 (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 Titrator Strips (100 PPM)
• Most Salt System Manufacturers recommend accuracy of
500PPM for you testing

• 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

Using STANDARDS to Confirm
Accuracy of your results

• Standards are used in an analytical
chemistry laboratory to verify the
accuracy of a test
• Standards are now available for pool
service professionals
What is a “STANDARD?”

• To verify the working condition of your instrument
or test method
• To verify your results are accurate
• To ensure correct testing procedure is followed
• To verify reagents are good
Why use a “STANDARD?”

• Food, Medical, and Drinking Water
Agencies (Government regulators and
inspectors) require that your testing
equipment be confirmed by Standards
regularly.
• Liability is a big motivator
Why use a “STANDARD?”

• Ready Snap 1P requires no dilution: just twist open, fill test
cell with sample, and run test
• Can be used with most instruments and test methods
• Ampoule (10 ml of solution) contains Standard that is used
to verify your pool testing procedure and reagents
• Ready Snap 1P are in plastic ampoules and are ideal for
pool service technicians
EXAMPLES OF
STANDARDS

•Snap open a Ready Snap
1P Method Verification
Standard by twisting the
top 180°
Using READY SNAP with TITRATION STEP 1

• Squeeze plastic ampoule
to fill CELL to capacity
Using READY SNAP With TITRATION STEP 2

∗ Add test tube sample to test
bottle
∗ Add colorimetric reagent
(powder) to test bottle
∗ Color will change from clear to
red due to the presence of
Calcium Hardness
Using READY SNAP With TITRATION
STEPS 3 & 4

• Start titration: add drop by
drop (count drops) Titration
Reagent to test bottle and
mix between each drop.
Observe color
• Observe when color
changes to PURPLE this
indicates titration is near
completion
Using READY SNAP With TITRATION
STEPS 5 & 6

• BLUE color
indicates end point
(8 drops used)
• Multiple 8 X 20
equals 160PPM
Total Hardness
• According to chart,
this is borderline
value
• Typical for titration
accuracy
Using READY SNAP With TITRATION STEP 7

• Fill test vial with
standard
• Dip test strip in
standard sample
for 5 seconds
Using STANDARDS
in a STRIP SCANNER

• Wipe excess liquid
with paper towel
according to
procedure
• Place strip into
scanner channel
Using STANDARDS
in a STRIP SCANNER

• Turn on the Photometer and
rinse out 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
CELL of the remaining water
drops
STEP 2

• Select the MENU for the
test method procedure you
need verified (Calcium
Hardness in this example)
and run the test method
• Verify the displayed value
result against the Solution
Value chart (Next Slide)
Using READY SNAP With PHOTOMETER
STEP 3

∗ Run the test method as you
do normally using the correct
procedure
∗ Compare the displayed value
against the assigned value
chart provided below and on
back
STEP 4

• If your value is
within the
acceptable range,
you are operating
the photometer
correctly for this
MENU test method
• If your value is
borderline, review
the manual and
the proper
procedure
STEP 5

READY SNAP Standard for TESTING:

• 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 Chemist
Ivars@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/

Proper Testing in Salt Water Pools

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