English Instructor Manual (PDF) - Metric Version - National ...

NO PRODUCT LABEL CHEMICAL ADJUSTMENT
Amount of Chemical
(from Appendix B-2 or
product label)
Actual Pool
Volume in Gallons
Desired
Chemical Change
Total
160,000 Litres
2 mg/L
÷ 40,000 Litres
(From appendix B-2
or product label)
1
÷ mg/L
(From appendix B-2
or product label)
330 mL
(from product label)
X X 2 =
4 2,640 mL
Conversion: 2,640 mL ÷ 1,000 = 2.64 litres
Key Points: Briefl y discuss free chlorine, total chlorine and combined chlorine. Include a
discussion on how to reduce or prevent organic chloramines that includes the options of:
Water replacement, breakpoint chlorination (BPC), ultraviolet (UV)
Ozone, potassium monopersulfate and indoor air handling
Activity: Work the students through breakpoint chlorination chemical adjustment. Use the
following data: 208,000 litre pool with a FC = 1.5 mg/L, a TC of 2.3 mg/L and a pH of 7.4. Facility
uses calcium hypochlorite. Emphasize that the desired changes is a result of CC x 10 minus
existing free chlorine value. (see example on page 75 of the Pool & Spa Operator Handbook).
Use the same Chemical Adjustment Worksheet to perform the breakpoint chlorination calculation.
(There are several more sample calculations in the Pool Math Workbook that may also be used.)
Key Points: Discuss the source of minerals in pool water and their effect on pool water when they
are oxidized. Include:
Source of minerals such as fi ll water, inadvertent additions of lawn and landscaping
chemicals, algicides, and corrosion due to poor pool water chemistry
Cause of green, red, brown or black water and methods of correction
Key Points: Discuss other commonly used chemicals and their possible effect on pool water.
These include:
Algaecides – Used to eliminate algae from pool water. The most common algaecide
compounds include quaternary algaecides, polymeric algaecides, and metallic (copper)
algaecides.
Stain removers – Chelating agents bond the metals into larger compounds that can be
removed through fi ltration. Sequestering agents remove metals by dissolving them into
solution.
Water clarifiers are used to clear cloudy water. Emphasize that this is a temporary
solution to a bigger problem, usually poor fi ltration.
© 2014 National Swimming Pool Foundation® Page 63