Philosophy of Education and Educational Philosophy
Salt Pools 101 and the importance of constant testing
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2. Salt Water Pools 101
(And why strive for Accurate Test Results)
By Ivars Jaunakais
Friday, February 22, 2014
10:00 a.m.
2 CE hours
3. TODAY’S TOPICS
• History and benefits of salt pools
• Importance of balanced water
• Different and proper water testing methods and
techniques
• What tests are needed for salt pools
• Q&A
4. HISTORY OF THE
SALT POOL
•
•
•
•
Developed in Australia - 1965
80% of all Australian pools use salt
Introduced in USA - 1980
Popularity in USA caught on in the last 10 years
as technology improved
5. HISTORY OF THE
SALT POOL
• 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
6. CHLORINE IS GENERATED!
• Saltwater pools generate a steady flow of chlorine
• Traditional chlorine pools buy, handle and manually
add chlorine
• This steady flow keeps the chlorine level consistent,
and minimizes highs and lows for chlorine
7. SALT WATER BENEFITS
•
•
•
•
•
Salt water is gentler on skin, eyes, nose and hair
Simple and convenient maintenance
Environmentally friendlier (no chlorine to store)
Less expensive to operate in the long run
Less prone to algae problems
8. MAINTAINING A SALT POOL
• Adequate generation of Chlorine by Salt System
• Regular testing of water
• Cleaning and Maintenance
• Adequate circulation time
• Quality filtration
• Rain dilution of salt levels
• Know what’s in the make-up water to anticipate
problems you may be adding to the pool
• Back flushing effects?
9. TESTING IS VITAL
• Proper maintenance of a salt pool
requires routine testing
• Adds comfort and safety for bathers
• Avoids liability issues with owner
• Accurate testing keeps problems
at a minimum
• Testing helps to keep salt pool balanced
• Accurate Chlorine levels are needed to know
if Salt System is adjusted properly
10. TESTING IS VITAL
• Weekly testing of pH and chlorine
• Monthly testing for total alkalinity, calcium
hardness, metals, salt, and cyanuric acid
• Testing of salt levels need
to match the levels of salt
specified by the chlorine
generator manufacturer
11. SERVICE GOALS
• Happy customers
• Accurate and correct
maintenance, which
avoids customer
complaints
• Increase business with
service reputation
12. SALT POOL ISSUES
• pH levels rise due to constant electrolysis
(if problem continues consider adding Borate Buffer to 50PPM)
• Regular if not weekly muriatic acid additions may
be needed to keep pH OK
• Muriatic Acid lowers total alkalinity levels
• Monitor Cyanuric Acid levels
• Monitor Salt level
• Corrosion of metal parts
• Higher electricity use
13. ADDITIONAL ISSUES
•Control box settings
•Pool circulation time settings
•Salt and concrete
•Effect of backwash on plants
14. POOLSIDE TESTING
CHALLENGES
• Poolside testing often performed in
undesirable environmental
conditions
• Temperature, humidity, sunlight,
wind, and rain affect results
• Distractions including poolside
activity and noise
15. TESTING CONSIDERATIONS
•
•
•
•
•
Cost per test (varies $0.02 to $0.30 up to $10)
Time to run test (time equals money)
Ease of use
Portability and stability of tests
Compliance testing requirements if testing public
or commercial pools and spas
(meets Florida Health Department approval)
• Test gives good results with a test Standard
16. YOUR TESTING SHOULD…
• Be acceptable or compliant (i.e., Chlorine test uses
DPD indicator as required by Health Dept.)
• 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 (lower resolution gives better
accuracy)
• Be accurate (accurate test results give accurate
maintenance)
17. COMMON TESTING TOOLS
• Colorimeters (Photometers) and
reagents
• Titration or drop reagents
• Comparator test
• Test Strips
18. COLORIMETIC TESTS
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
19. TESTING TOOL #1
Photometer and Reagent
(Most accurate method)
• 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 0.01 PPM resolution; 0.03 PPM accuracy
• Hardness has 1 PPM resolution; 10 to 20 PPM accuracy
21. TESTING TOOL #2
Colorimetric (visual) titration
Commonly used FAS/DPD method
•
•
•
•
•
Visual color change determines concentration
End point color change must be monitored
Accurate counting of drops is required
Test is dependent on technique (swirling)
Math required (drops are multiplied by
concentration factor)
• Chlorine has 0.2 PPM (or 0.5PPM) resolution
and expect 0.6 PPM (or 1.5PPM) accuracy
• Hardness has 20PPM resolution; 60 PPM
accuracy
22. TESTING TOOL #3
pH and Chlorine COLOR COMPARATOR
• Fast and inexpensive
• Liquid reagents are known to have
stability issues
• Requires good visual judgment
• Chlorine has 1 PPM resolution and
3 PPM accuracy at lower levels
• pH has 0.3 resolution; 0.5 accuracy
23. TESTING TOOL #4
Multipad Test Strips
• Very Fast and inexpensive
• Ideal for Pools with no issues
• 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
24. COLOR BLINDNESS
Over 32 million Americans (8% or 1 out of 12 men) have
varying degrees of color blindness
27. TESTING
BEST PRACTICES
• 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)
28. TESTING
BEST PRACTICES
• Do not collect water sample
near return lines
• Note the temperature of water
to be tested (cold or hot water
can effect test results)
• Read test instructions for
procedure how to run test with
cold or hot water
29. 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
30. 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 possible.
• Don't swap/mix the caps on
reagent bottles to avoid
chemical cross contamination
31. 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
32. TESTING
BEST PRACTICES
• Add liquid reagents
carefully – make sure the
correct number of drops
are added to sample and
drops are equal and fullsized
• Mix reagents with test
samples thoroughly
33. 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
34. TESTING
BEST PRACTICES
• Record test results and maintain records for
each pool or spa
• Never dispose of tested samples/reagents in
the pool
• Rinse sample test vials and cells
immediately after testing
35. 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
37. IDEAL LEVELS for Salt Pools
CHEMICAL
Salt
IDEAL LEVELS
2700 to 3400 ppm
Free Chlorine
Cyanuric Acid
Total Alkalinity
Calcium Hardness
1.0 to 3.0 ppm
60 ppm (consider 20 to 40ppm)
80 to 120 ppm
200 to 400 ppm
Metals (Copper?)
Saturation Index
0 ppm
-0.2 to +0.2 (non-salt pools -0.5 to +0.5)
Nitrates at 0 PPM
38. BALANCED WATER
• Healthy Water is Balanced Water
• For balanced water 6 parameters to consider
and they are used to calculate (Langelier)
Saturation Index (SI)
1)
2)
3)
4)
5)
6)
pH
Total Alkalinity
Calcium Hardness
Total Dissolved Solids (TDS)
Temperature
Cyanuric Acid (CY)
39. BALANCED WATER
• 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 between -0.2 to +0.2)
40. BALANCED WATER
•
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 scaleformation, & discoloration
•
Minimizes potential Health hazards from disinfection by-products
(combined chlorine is especially a problem for indoor pools/spas)
•
Maintains compliance with Florida Health Dept regulations
“Majority of pool problems are caused by unbalanced water”
41. CHEMICAL SOURCES
IN POOL 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)
• 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.
42. OTHER THINGS IN
POOL WATER
• Bather sweat, urine, dirt, lotions, sunscreen,
cosmetics, soap, deodorant, hair spray, etc.
• Environmental items - debris, dirt, leaves ,
vegetation, etc., contribute to problems
• Disinfection by-products - trihalomethanes,
haloacetic acids, chlorate, nitrogen trichloride,
etc.
• Rain water (can dilute your balanced water)
44. 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
45. 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
• 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)
47. 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. If your 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
49. 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
• 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
50. CY AND TA
• Cyanuric Acid (CY) effects Total Alkalinity (TA)
in the pool
• CY elevates TA and is influenced by the pH:
CY of 40 PPM with 7.0 pH elevates TA by 8.8 ppm
CY of 40 PPM 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.
• One more reason to keep CY below 40 PPM
51. CY AND TA
• Keep CY levels at or below 40 ppm the TA effect
averages about 10 ppm and so below 40 PPM CY
you can mostly ignore CY influence on TA.
• This is another reason to keep CY under 40 PPM
52. CYANURIC ACID IN THE U.S.
One study 20 Years ago reported:
• Average concentration – 76 ppm
• Maximum concentration – 406 ppm
• 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 60 PPM because
higher levels have potential problems
53. MY CYANURIC ACID (CY)
GUIDELINES
• 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 level is 60 ppm)
• 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. Salt pools
eliminate this practice.
54. 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
55. CYANURIC ACID
TEST METHODS (resolution)
• Photometric (1 ppm)
• Visual black dot comparator
(over 20 ppm)
• Test Strip
(over 50 ppm)
56. CYANURIC ACID
TESTING IN THE FUTURE
• Use a Photometric method to get
accurate test results for Cyanuric Acid
• Very important when you want to keep
CY between 20 - 50 ppm
57. 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
58. TOTAL ALKALINITY (AL)
• Total Alkalinity is key to pH water balance
• Recommended that it should be adjusted
FIRST, before 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)
59. TOTAL ALKALINITY (AL)
Low Alkalinity (below 80 PPM) 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
60. TOTAL ALKALINITY (AL)
• 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).
63. pH
•
•
•
•
•
•
•
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)
64. 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
67. pH Testing Methods (resolution)
• pH meter (0.01 or 0.1)
• Photometric (0.1)
• pH comparator (0.2)
• Test Strips (0.2 or 0.3)
68. 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 ?
70. CALCIUM HARDNESS (CA)
• Pool & spa water must have a certain amount of
Calcium
• Calcium Hardness, when outside optimal range, can
allow corrosion or scaling
• Make-up water with high calcium is “hard water”
• Make-up water with low calcium is “soft water”
• Low water hardness allows corrosion of calcium rich
surfaces such as concrete, plaster, & grout
72. TOTAL DISSOLVED SOLIDS
(TDS)
• TDS = 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
74. HIGH TDS?
High TDS levels ( over 1500 PPM) 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 3500 TDS
75. TDS 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
76. TDS TESTING
• 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
77. 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
78. SI and RELATIONSHIP OF
BALANCED WATER
• 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
80. SANITIZER AND DISINFECTANTS
• The pool environment is constantly exposed to
new contaminants, two important
considerations:
1. Sanitize water to kill microorganisms
2. Oxidize organic contaminants
81. 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
82. CHLORINE
• Chlorine is the most popular worldwide
sanitizer, disinfectant, algae killer and oxidizer
• Chlorine doubles as a sanitizer and oxidizer
• Chlorine is most effective under certain
conditions (pH)
83. CHLORINE
• Effective against a broad range of
microorganisms
• Inactivation of pathogens depends on contact
time
• In the United States, Health Departments
require all public pools to be routinely tested
for chlorine
84. GERM INACTIVATION TIME IN
1 ppm CHLORINATED WATER
GERM
E. Coli O157:H7
INACTIVATION
TIME
Less than 1 minute
Bacterium
Hepatitis A
About 16 minutes
Virus
Giardia
About 45 minutes
Parasite
pH 7.5,
Cryptosporidium77 F
About 15300 minutes
Parasite
(10.6 days)
85. CHLORINE SOURCES Salt
Systems generate HOCl
- or NaOCl equivalent
Chemical
Name
Chemical
Formula
Form
%
Chlorine
Chlorine
Gas
Cl2
Gas
100%
Calcium
Ca(OCl)2
Solid
65-70%
NaOCl
Liquid
~12%
Hypochlorite
Sodium
Hypochlorite
86. 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
87. CHLORINE CHEMSTRY
• The sum of Hypochlorous acid
(HOCI) and Hypochlorite ion
(OCI ¯ ) is called free chlorine, and
the chemical equation or relationship
is:
88. HYPOCHLOROUS ACID REACTIONS
• Two chemical reactions impact Hypochlorous acid
as a disinfectant:
• FIRST REACTION hydroxide ion (OH¯)
• OH¯ is available in aqueous solution especially
when pH level is above 7 which causes
Hypochlorous acid to form Hypochlorite ion
89. 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)
91. 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
to form chloramines
• Chloramines are less effective disinfectants
• Active chlorine can be transferred from inorganic
chloramine to amine (organic) containing
compounds
92. BREAKPOINT CHLORINATION
• Eliminating the combined chlorine and the
ammonia / 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
93. TOTAL CHLORINE
• Total chlorine = free chlorine + combined
chlorine
• Free chlorine and total chlorine can be
monitored by automated equipment and
confirmed by poolside testing for swimmer
protection
94. DPD CHLORINE TESTING
• 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
95. EPA ACCEPTED
CHLORINE TEST METHODS
(FREE AND TOTAL)
• 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)
96. TOTAL CHLORINE (TC) =
FREE CHLORINE (FC) + COMBINED
CHLORINE
• Combined chlorine = TC - FC
• Free chlorine = 1.58 ppm (FC)
• Total chlorine = 1.89 ppm (TC)
• Combined chlorine = 1.89 – 1.58 = 0.31 ppm
Combined chlorine is above the recommend level of 0.20
ppm and suggests pool needs to be shocked: in this
example ( 10 X 0.31 = 3.1 ) this pool can be shocked by
increasing the pool chlorine level by 3.1 ppm
98. 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
99. 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
100. PHOSPHATE
• Phosphorus is 0.12% of the earth’s crust
• Human bones and teeth contain calcium
phosphate
• Phosphate is an essential nutrient for algae
growth
• Phosphate testing is challenging below
0.2PPM (200 ppb)
101. HOW PHOSPHATE GETS
IN WATER
• Runoff from lawns
• Rain water
• Bathers
(sweat and urine)
• Pool treatment chemicals
• Blown in leaves and debris
102. CONTROL ALGAE BY
CONTROLLING 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
103. SALTS THAT REMOVE
PHOSPHATES
• 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+
104. 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
105. 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 1000 PPB
phosphates)
106. 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 0.1 PPM or 100 PPB
• If Chlorine is maintained above 4PPM and CY
below 60PPM pool can tolerate 0.5PPM (500
PPM) phosphate without algae problem.
107. 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
108. 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.
109. 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)
110. 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 Titration Strips (100 PPM)
Most Salt System Manufacturers recommend accuracy of 500PPM for you
testing
111. TURBIDITY
• 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)
112. STRIVE FOR BEST RESULTS
• Pride in your work
• Customers expect it
• Health Departments
require it
• Liability issues are bad
for business
114. 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/