Swimming pools and spas || with Errorless Answers.
Clarity in a pool is necessary for two reasons.. correct answers -safety. It must be possible to see
a person in difficulty at the bottom of the pool
-disinfection. Water containing turbidity requires a high chlorine content in order to ensure
proper disinfecting.
What is turbidity? correct answers Turbidity is caused by dirt, debris and algae growth. Particles
that cause turbidity can settle at the bottom of the pool as well as rise to the surface.
Recirculating from the top and the bottom of a pool is desirable.
Recirculating from the top of a the pool... correct answers Through gutter and skimmers, is
important. 50% of the recirculated water must be taken off the top of the pool. It is important this
is maintained when the pool is not in use because quiescent water permits oils and other floating
material to remain on the surface. If adequate recirculating is not possible, overflowing when idle
is helpful in removing excessive surface contamination.
Sediment and solids from the bottom of the pool... correct answers Can be removed by
vacuuming. Inspection of the bottom of the pool before swimming will indicate if cleaning is
necessary.
Suspended materials in the pool... correct answers Can be removed with filters. A slurry feed
should precede diatomaceous earth filters (D.E), whole alum is added if sand filters are installed.
It is important that the correct chemical or slurry dosage be used and that the filters be
backwashed regularly.
What are some methods in gauging turbidity? correct answers -A common method is that the
main drain should be visible from any point while standing on the deck at the deep end of the
pool. This drain must be clearly visible in the morning from any point on the pool deck and in
well-operated pools will be visible all the time throughout the day. If the main drain is not
visible, do not open the pool.
, -an experienced operator can tell by casual observation. In addition to being clear, good pool
water has a sparkling light blue colour. A greenish blue colour is often associated with algae
growth or low pH.
What is chlorination? correct answers Chlorination is necessary to prevent disease-causing
bacteria from spreading from one person to another while swimming. It is the operators
responsibility to maintain sufficient free residual chlorine in the pool water. This is a minimum
of 0.5 milligram per litre (mg/L). Chlorine may be added in the form of gas by means of a gas
chlorinator or may be added in form of a calcium or sodium hypochlorite solution. Gas feed
chlorinators are required in public pools to provide the capacity necessary for good chlorine
control. 1.3 kilograms of chlorine per day for each 45,000 cubic decimetres (dm^3) of water in
outdoor pools.
How to test for residual chlorine correct answers A comparator (test kit) which is an instrument
or machine for comparing anything to be measured with a standard measure, is necessary.
Diethyl-p-phenylene diamine (DPD) tablets are added to a measured amount of water (a small
tube of water). The DPD tablet combines with chlorine to produce a red colour, which, when
matched against coloured glass standards, indicated the chlorine residual in mg/L.
pH correct answers The pH of water is the indication of whether water is acidic or basic.
-Neutral water has a pH of 7.
-Acidic water has a pH between 0 and 7.
-basic water has a pH between 7 and 14
What is the recommended pH level of pool water? correct answers Between 6.8 and 7.6. Below
7.4 pool water becomes corrosive, piping may deteriorate. Levels above 8.0, precipitation of
calcium carbonate may occur causing milky water and reduced effectiveness of chlorination.
What is common to help maintain a good pH? correct answers A continuous feed of soda ash to
balance the pH levels.
How do you test for pH? correct answers Certain chemical dyes are sensitive to acids and bases.
These dyes change colour gradually as the pH of the solutions changes.
Clarity in a pool is necessary for two reasons.. correct answers -safety. It must be possible to see
a person in difficulty at the bottom of the pool
-disinfection. Water containing turbidity requires a high chlorine content in order to ensure
proper disinfecting.
What is turbidity? correct answers Turbidity is caused by dirt, debris and algae growth. Particles
that cause turbidity can settle at the bottom of the pool as well as rise to the surface.
Recirculating from the top and the bottom of a pool is desirable.
Recirculating from the top of a the pool... correct answers Through gutter and skimmers, is
important. 50% of the recirculated water must be taken off the top of the pool. It is important this
is maintained when the pool is not in use because quiescent water permits oils and other floating
material to remain on the surface. If adequate recirculating is not possible, overflowing when idle
is helpful in removing excessive surface contamination.
Sediment and solids from the bottom of the pool... correct answers Can be removed by
vacuuming. Inspection of the bottom of the pool before swimming will indicate if cleaning is
necessary.
Suspended materials in the pool... correct answers Can be removed with filters. A slurry feed
should precede diatomaceous earth filters (D.E), whole alum is added if sand filters are installed.
It is important that the correct chemical or slurry dosage be used and that the filters be
backwashed regularly.
What are some methods in gauging turbidity? correct answers -A common method is that the
main drain should be visible from any point while standing on the deck at the deep end of the
pool. This drain must be clearly visible in the morning from any point on the pool deck and in
well-operated pools will be visible all the time throughout the day. If the main drain is not
visible, do not open the pool.
, -an experienced operator can tell by casual observation. In addition to being clear, good pool
water has a sparkling light blue colour. A greenish blue colour is often associated with algae
growth or low pH.
What is chlorination? correct answers Chlorination is necessary to prevent disease-causing
bacteria from spreading from one person to another while swimming. It is the operators
responsibility to maintain sufficient free residual chlorine in the pool water. This is a minimum
of 0.5 milligram per litre (mg/L). Chlorine may be added in the form of gas by means of a gas
chlorinator or may be added in form of a calcium or sodium hypochlorite solution. Gas feed
chlorinators are required in public pools to provide the capacity necessary for good chlorine
control. 1.3 kilograms of chlorine per day for each 45,000 cubic decimetres (dm^3) of water in
outdoor pools.
How to test for residual chlorine correct answers A comparator (test kit) which is an instrument
or machine for comparing anything to be measured with a standard measure, is necessary.
Diethyl-p-phenylene diamine (DPD) tablets are added to a measured amount of water (a small
tube of water). The DPD tablet combines with chlorine to produce a red colour, which, when
matched against coloured glass standards, indicated the chlorine residual in mg/L.
pH correct answers The pH of water is the indication of whether water is acidic or basic.
-Neutral water has a pH of 7.
-Acidic water has a pH between 0 and 7.
-basic water has a pH between 7 and 14
What is the recommended pH level of pool water? correct answers Between 6.8 and 7.6. Below
7.4 pool water becomes corrosive, piping may deteriorate. Levels above 8.0, precipitation of
calcium carbonate may occur causing milky water and reduced effectiveness of chlorination.
What is common to help maintain a good pH? correct answers A continuous feed of soda ash to
balance the pH levels.
How do you test for pH? correct answers Certain chemical dyes are sensitive to acids and bases.
These dyes change colour gradually as the pH of the solutions changes.
