AL Mesk Pools | Swimming pool system filters | THE POOL SYSTEM

The swimming pool system filters and helps maintain the clarity of the pool water. As the water
is circulated by a properly designed system the water evenly distributes the chemicals that are
added to the pool to control purity and chemical balance.
The filtration system re-circulates and filters the water in the pool. It enables the initial water
supply to be used over and over again, adding just the little water necessary to backwash the
filter and compensate for evaporation and splash-out.
The filtration system is composed of four elements: the filter, a
pump and motor, an automatic surface skimmer, and
recirculating piping.
The PUMP circulates the pool water through the filtration
system; mixing and sanitizing chemicals.
The water passes through the FILTER which removes unwanted
debris. The filter used for your pool is a High-rate sand filter. This
filter is a pressure vessel moulded from a chemical resistant
thermoplastic. It has a system of drains and water distribution that
maintains a non-turbulent flow through the filtering media. The
media consists of a special grade of sand which if properly maintained
will last for several years.
To clean the filter sand the filter must be backwashed ie, the flow
through the filter must be reversed. For your filter this is done
conveniently with the aid of the multiport valve mounted on the top of
the filter. About 80 gallons to 400 gallons of water is used during the
The PLUMBING SYSTEM is designed to circulate all the water through the filtration system.
Normally, water is drawn from the pool through the main drain and the surface skimmer; passes
through the suction lines to the pump and filter and then returns to the pool via return lines and
return inlet fittings.
Filtration, chemical treatment, and cleaning are the three essential methods of keeping the pool
water clear, clean and free of bacteria. Beginning from the time the pool is filled, the job of
maintaining safe pool water continues the year around for the life of the pool.
You can hire a pool service company like AL MESK POOLS to do the job, or do the work
The Role of Filtration:
The filtration system is the primary method for removing solid material that clouds the water; it
also disperses the pool chemicals throughout the water so they can do their job.
A properly designed system should pass all the water in the pool through the filter within a
given period of time usually 6 to 8 hours. This is called turnover rate. Without proper circulation
the pool will have dead areas where the water stagnates and is never or seldom filtered, even
though the filter may be working perfectly.
Whenever poor water clarity or chemical imbalance become apparent, increase the filtration time
until the condition is corrected. After filling the pool for the first time, you’ll need to run the
filter continuously until the water is clear. In properly filtered and chemically treated water, you
can clearly see the main drain in the pool. A timer fitted to the pump circuit allows the pump to
turn on and off automatically.
Pool Water Chemistry
Treating your pool water with chemicals maintains the chemical balance, disinfects the water,
and keeps it sparkling clear. The water must be tested regularly for various characteristics and
the correct amounts of certain chemicals must be added if required.
How to test your pool water:
Proper water testing is your major guarantee against the
development of serious problems. The TEST KIT supplied to you
will provide the information necessary to determine the chemical
The test kit enables you to test for pH and disinfectant (Chlorine)
residual. Testing is a simple process. You fill the small tube with pool water, add a reagent in
the form of a tablet or test solution and check the reading. The treated water is then compared to
a color standard. The best time to test the water is in the early evening. Avoid surface water
when you fill the tube. Take a sample from a depth of at least 12 inches. Look at the color
against a light background and read the test within 4 to 5 seconds after adding the reagent.
Always rinse the tube before and after use. Follow the instructions for testing carefully.
Swimming pools and spas are subject to constant contamination from foreign
matter brought in by swimmers, wind and articles used in and about the water.
Such contamination includes particles of dirt, organic matter, bacteria, algae, hair,
makeup, suntan and body oils, leaves, mineral residue from chemicals and debris.
process of removing
g this insoluble matter from
Filtration is the mechanical p
swimming pool and spa water. Pool water carrying particulate matter, solids and
debris is passed through filtering media that allow the water to return to the pool
clear. Water clarity is important for appearance, hygiene and safety.
The US National Sanitation Foundation recommends that pool water turbidity
(1/clarity) shall not exceed 0.5 NTU ( Nephelometer Turbidity Units). However for
short times during peak bather loading, this shall not exceed 1.0 NTU, and the pool
filtration system shall be capable of returning this water to 0.5 NTU within 8 hours
following this peak use.
A common method of noting water clarity is to be able to see the pool drain clearly
from the pool deck or to see clearly a 2” disc with black and red quadrants through
15 feet (4.6m) or water.
Th factors
f t
thatt determine
d t
i water
t clarity
l it are flow
t amountt off filtering
filt i area and
effectiveness of filter media.
Once equilibrium is achieved, a six-hour turnover will result in 99% clarification
assuming that the filter medium is effective and the filter is properly sized to
accommodate the amount of contamination introduced into the water.
y of p
pool water should be equal
to or better than the q
y of drinking
The q
Number of times Pool
Volume is filtered
each 24 hrs
(turnovers per day)
Hours required to
Filter Pool Volume
(turnover period)
Percent Clarification
of Pool water after
equilibrium is
Number of days
required to attain
Kuwait’s first choice since 1982
: 24833046 – 24831971
Fax: 24842389
Water balance
Controlling the chemical balance of pool water is vital. The ideal range is slightly on the alkaline
side, between 7.4 and 7.6 on the pH scale. If the pH is too high (alkaline), disinfectants are less
effective in destroying bacteria and algae; water will be cloudy, scale can develop and the filter
can be blocked. If the pH is too low (acidic), it will cause eye and skin irritation, corrosion of
metal parts, and etching and discoloration. Because over acidity can be the most serious, do not
allow the pH to get below 7.2.
Testing pH is simple. The water sample in the test kit will change color according to the pH.
During the summer, the pH should be tested three times a week. Always test for pH after a
storm or at other times when large quantities of contaminants have been carried into the water.
Contact your pool company for chemicals to raise or lower the pH of the pool water.
Disinfecting the pool water
Bacteria are the main cause of unsanitary pool water. These microscopic organisms, some of
them harmful, invade pool water by means of carriers – mostly people. Particularly in pools
with heavy use, bacteria control cannot be overemphasized.
Chlorine is by far the most popular disinfecting agent. It has proven to be effective and easy to
Add chlorine only in the evening or early morning hours. Keep the filtration system on to
distribute the chlorine in the pool.
Whenever you add chlorine, it immediately goes to work killing algae and bacteria, but in the
process these same algae and bacteria destroy some of it. The amount of chlorine used up in this
manner is the chlorine demand of the water. The amount of disinfectant left in the water is
referred to as the chlorine residual. This free residual keeps the pool sanitary, and only a small
amount of it is required.
Pool water also contains ammonia and other compounds of nitrogen, particularly ammonia
nitrogen. Chlorine and ammonia combine to form chloramines which cause the unpleasant odor
often associated with chlorine, particularly pungent if the pH is low. If you can smell the
chlorine, there isn’t enough residual chlorine in the water, as chlorine in an uncombined state is
practically odorless.
The chlorine residual, that which is not combined with nitrogen, should never drop below 0.5
ppm it must be ideally between 0.5ppm and 1.5 ppm. Chlorine residual is tested in the same
way as the pH. Follow the instructions on your test kit.
Sunlight, water temperature, heavy pool use, and wind can all deplete the chlorine residual.
Regular use of chlorinated iso-cyanurate should keep the residual at a safe level. But a day of
heavy use can destroy all the chlorine in the water unless you take preventive measures by
adding an extra dose before swimmers arrive. Even then, the supply may have to be replenished
at the end of the day to restore the residual level.
Superchlorination involves adding 5 to 7 times the normal dose of
chlorine to pool water to burn out nitrogen compounds and human
Superchlorination must be done when the combined chlorine
reading is higher than .2ppm, or about every 2 weeks during the
swimming season. Superchlorination should be done only after
sundown, since the UV sun rays are likely to destroy some of the
chemical. Close the pool to swimmers until the residual level drops
to normal: 1.0 to 3.0 ppm.
Chlorinated isocyanurates are the chlorine compounds with cyanuric acid base. These are the
most popular and easy to use forms of chlorines. These chlorine compounds are easy to use,
dissolve readily, leave no calcium residue to damage filter media, and do not appreciably alter
the pH. They’re available in tablets, sticks, or granulated form.
Continued use of chlorinated isocyanurates may cause the cyanuric level in the water to increase
over a period if water is not discarded by backwash or splashout. If the cyanuric acid in the
water tests out at over 100ppm, the pool may have to be partially drained and refilled with fresh
water. Your pool service company can test the cyanuric acid level in the pool.
The granulated type of fast dissolving chlorine may be added directly to the pool and is
particularly good for spot treatments of clinging algae.
Good water maintenance normally will keep algae under control. If the water takes on a
greenish or mustard colored cast and black or dar green spots appear on the surface finish, you
have algae.
There are two types of algae: free floating and clinging. Some of the clinging varieties may resist
all efforts and hang on as black, green or brown patches.
There are several ways to get rid of algae.
Check the total alkalinity of the pool. Have it adjusted 80-120 ppm. Adjust the pH to 7.2 to 7.4.
Then superchlorinate. Shut down the filter for about 24 hours. Brush the walls briskly, restart
the filter and vacuum away the dead algae. To get rid of black spots, brush the pool and turn the
pump off. When the water becomes still, carefully pour trichlorinated isocyanurate into the pool
so it covers the area. Brush again the next day. Then turn on the pump to filter out the debris.
Do not allow swimmers in the pool during this period.
Pouring liquid chlorine right on top of them can destroy persistent colonies clinging to interior
surfaces. However, only the outer layers of cells may be killed, leaving surviving cells beneath
to re-emerge when growth conditions are favourable.
Ask your pool service company for recommended Algaecides.
If algae persist, call the pool service company.
Check chlorine residual and pH after heavy chemical treatments, and do not allow swimmers in
the pool until the water is properly balanced and the chlorine is at a safe level.
A pool surface can be stained by debris, metal objects, algae and mineral deposits. Yellow or
reddish brown stains may be caused by iron in the fill water. Too much acid added to the water
at one time can cause stains. Maintain the proper pH to help prevent staining. Hairpins, toys or
other metal objects dropped into the pool should be removed immediately to prevent rust stains.
Corrosion and electrolysis.
Corrosion can result from an over acidic condition, improper use of acid chemicals, or oxidation.
Corrosion also can be caused by electrolysis. Whenever two different metals come in contact
with chemically treated water, a small electrical current flows between the metals. This current
does not give an electric shock, but it can cause corrosion of active metals such as iron and
produce rust spots on metal.
Maintenance of your swimming pool begins as soon as you fill it with water and continues the
year around. Summer and winter, your pool needs some attention to keep the equipment
functioning smoothly, the water clean, and the pool shell in good condition.
Pool maintenance requires a regular schedule of routine work intended to make your pool
pleasant to swim in and to ward off serious problems.
You can contact a pool company like AL MESK POOLS to maintain and chemically treat your
pool. The monthly charge depends upon the number of service calls and the pool size.
Maintenance Equipment
Very few pieces of equipment are required to maintain a pool:
A Vacuum cleaner or vacuum head, a leaf skimmer or net, and brushes.
The vacuum cleaner works from the vacuum point
that’s part of the filtration system or through the
skimmer. The cleaner consists of a suction head,
wheels for mobility, a nylon brush for removing dirt,
a floating hose from the suction head to the vacuum
fitting and a handle. The cleaner is hooked up to the
vacuum fitting and is pushed slowly around the
bottom of the pool. Water, dirt and debris are pulled
into the filtration system. Leaves and other large
objects, such as pieces of paper, are caught in the
strainer basket; smaller particles are removed in the
filter. The clear water is then returned to the pool
through the inlets.
The leaf skimmer is an aluminum or plastic frame
with a plastic mesh skimming net.
Vacuum Hose
Test kit
Leaf Skimmer
Nylon Brush
Vacuum Head
Brushes with nylon bristles are usually recommended for long life. You may also need a
stainless steel brush for removing algae, rust stains and entrenched dirt.
Aluminum handles that fit the vacuum cleaner, leaf skimmer, and brushes are available. One
handle is enough since it can be used interchangeably with all the cleaning tools. The telescopic
handle supplied is helpful.
Regular cleaning procedure:
There is no set pattern for pool cleaning. You can work out a procedure that best suits your
particular situation. The following maintenance procedure serves as a good starting point:
Use the leaf skimmer to collect debris floating on the surface of the pool or lying on
the bottom. It’s much easier to skim the surface than dredge the bottom, so use the
leaf skimmer often to remove debris before it can sink.
Clean the border and walls. The scum line that forms at the water line is a
combination of oil and dust and can be cleaned off with household powders and a
sponge. Never use steel wool to clean tile. If heavy scale persists, call a pool
professional. Brushing the pool walls requires even coverage rather than strength.
Brush the walls all the way down to the floor, so the dirt can be picked up with the
vacuum cleaner. Whenever possible brush toward the main drain so some of the dirt
will be pulled into the filter system as you work. Start at the shallow end and work
toward the deep water. Overlap your strokes so the entire surface receives a good
Clean the strainer baskets in the skimmer and pump. Make sure all the debris is
removed so that there is maximum suction.
VACUUM THE POOL at least twice a week and more often if there is an extra heavy
dose of debris.
The vacuum hose must be completely filled with water before it is attached to the
vacuum point on the filter line.
Slowly submerge the hose in the water to eliminate air bubbles. Holding one end
against a return line with the hose in the water will also work. Don’t lift the
vacuum head out of the water while it is in operation.
While operating the vacuum close the valves on the main drain and the skimmer
line and open the valve on the vacuum line. The water level in the pool should be
above the vacuum inlet so no air can reach the fitting and enter the lines.
Work the vacuum slowly back and forth and overlap each stroke to avoid missing
any spots.
Try not to run fresh water into the pool while vacuuming.
It is sometimes advisable to vacuum directly to waste, if there are heavy
precipitates or an unusually high soil load to be removed. This cuts down
maintenance of the filter media.
Backwash and service the filter. The equipment will last longer when backwashed
regularly and thoroughly.
BACKWASHING THE FILTER can be done by turning the multi-position valve to
the backwash position. This reverses the flow of water through the filter, raises the
sand bed, and cleans it. The reversed flow carries the dirt and debris out through the
waste line.
Always turn the pump off before turning the multi-position valve.
• With the valve in the backwash position, open the valve on the waste line
and turn on the pump. Allow it to run for 2 to 4 minutes until the wastewater is clear. (You can watch the water through a sight glass in the filter
• Shut off the pump and turn the valve to the rinse position, allowing the
water to flow through the filter bed in the normal direction and into the
waste line.
• Turn the pump back on and run for about 15 to 20 seconds. This resets the
sand bed and prevents any dirt from reentering the pool when you start
filtering again.
• Shut the pump off and turn the valve to filter position, the normal
position for routing the water through the filter and back to the pool. Turn
the pump back on. Close the valve on the waste line.
• The valve has other positions as well: The recirculate position by-passes
the filter and can be used until the filter is serviced. The waste position
discharges water from the pool directly into the waste line. Use this
position to lower the water level or to get rid of a lot of dirt when
vacuuming. (Remember to open the valve on the waste line). The closed
position is used when the system is not running. Never run the pump
with the valve in the closed position.
Test the water.
Add Chemicals
Hose the coping and deck. Keep the spray directed away from the pool to prevent
silt from being washed into the clean water.
Recommended Procedure for
Backwashing the Filter
Note the positions on the multi-port valve
Main drain valve open
Skimmer/Balance tank valve closed
Vacuum valve closed
Switch off pump
Open waste line valve
Turn multi-port valve to BACKWASH
Multi-port Valve
Switch on pump
Watch dirt in sight glass
Turn off pump after 3 mins
Turn multi-port valve to RINSE
Switch on pump for 1 min
Switch off pump
Turn multi-port valve to FILTER
Close the waste line valve
Switch on pump
Open skimmer/Balance tank valve as
Kuwait’s first choice since 1982
: 4833046 – 4831971
Fax: 4842389
Basic Water Testing
• Check the test kit
• Rinse the container with pool water
• Dip the container into the pool water
and fill with pool water from at least 40
cm below
• Check the water level in the container
• Add 5 drops of yellow cap (chlorine
test) reagent to water in the chlorine
• Add 5 drops of red cap (pH) reagent to
water in the pH side.
• Fix both the caps on the container.
• Shake the container to mix the reagent
and water.
• Check the colour against a white back
• Note the readings.
• Empty the container back
into the pool.
• Rinse the container.
Kuwait’s first choice since 1982
: 4833046 – 4831971
Fax: 4842389
Maintaining the support system: filter, pump and other parts, involves keeping everything in
working order and watching for and correcting small problems before they develop into
expensive repairs.
The obvious time to clean the filter is when the water is no longer clear. The best time, though, is
before the quality of the water deteriorates. To determine when this is, look for an increase in
pressure registered by the pressure gauge on the filter tank. Record the pressure reading when
you start up a clean filter with clean strainer baskets in the pump and skimmer. Depending on
the filter and the rest of the system this pressure ranges from 6 psi to 20psi. When the pressure
has increased by 8 to 10 psi, it’s time to clean the filter. Regardless of pressure readings, the
filter must be cleaned at least once a week.
If the pool is properly treated, the filter will require no extra maintenance. But chemical
imbalance in the water can harm the filter. Water high in pH and calcium precipitation can turn
the sand bed into a solid chunk of scale. If you’re having to backwash your filter often and
noticing inadequate filtering, scale, and dirt in the pool, open the filter and check the condition of
the bed. If you find dirt deep in the sand, it’s time to replace the sand. How often you need to
change the sand depends on the amount of dirt entering the pool; generally, it needs to be done
only once a year.
Pump & Motor:
The type most often used for pools has self-lubricating bearings and seals that don’t need
lubricating. Usually you’ll need to remove hair, leaves, and other debris from the strainer basket
when you vacuum the pool or when you’ve shut off the pump to clean the filter.
To remove the basket, shut off the pump; turn off the valves on the pipes from the skimmer,
main drain and inlet. Then remove the cover, lift out the basket and clean it. After the clean
basket is in place, replace the cover and tighten it securely. Open the valves on the skimmer and
main drain pipes and turn the pump on.
Though the pump is self-priming, it may lose prime when the basket is
cleaned or when there’s an air leak under the basket cover or elsewhere
in the system. To prime the pump, remove the basket cover, fill the
pump to brim with water and quickly replace the cover and start the
If the pump doesn’t work call the pool service company.
Cloudy, milky, or turbid water
• Operate the filter for a longer time
• Backwash the filter
• Check and adjust chlorine and pH
• Check for air leak in the intake lines to pump
• Make sure the filter multi-position valve is in filter position.
• Check skimmer and pump strainer baskets for debris
• Add water clarifying agent.
Green or brown cloudy water
• Algae
Cloudy or hazy water with rapid rise of pH
• Early algae growth
Brown or green slime on pool surfaces
• Algae
Black spots on pool surfaces
• Black algae
Reddish brown, brownish black, blue or blue green water.
• Metal ( iron, copper or manganese) in water. Call pool service company
Clear green water turning to reddish brown
• Indicates iron
Eye and skin irritation
• Test and adjust pH
Eye and skin irritation, strong chlorine smell
• Test and adjust pH; superchlorinate
Low water flow
• Backwash sand filter.
• Check for air leaks in intake lines
• Check for restrictions in intake and return lines
• Check pump and skimmer strainer baskets for debris
• Be sure proper valves are open
Filter needs frequent backwashing
• Check for algae, if present treat accordingly.
• Check and adjust chlorine and pH levels
• Clean sand filter with special cleaner ( See pool service company)
• Check surface of sand in sand filter; if cracked or crusted, remove 1” sand.
Pump motor doesn’t start
• Blown fuse or tripped circuit breaker
• Loose electrical connection or broken wire
Pump motor noisy
• Loose connections between pump and motor
• Worn bearing in motor
Pump runs but doesn’t pump
• Low level in pool; add water
• Clogged filter- backwash
• Air leaks in intake lines
• Loose pump impeller
• Pump has lost its prime
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