Recommended Maximum Pool Water Temperatures
• Competitive swimming & diving, Fitness swimming, Training . . 27 deg C
• Recreational, Adult teaching, Conventional main pools . . . . . . . 28 deg C
• Children's teaching, Leisure pools . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 deg C
• Babies, Young children, Disabled & handicapped. . . . . . . . . . . . .30 deg C
High water temperatures are usually unnecessary and may cause damage or reduce the life span of many items of pool equipment. Liners may lose their elasticity, - pool covers will have a reduced life, - plastic fittings may become brittle and break, - filter underdrains or laterals may become distorted or damaged, - socket unions may loose their shape and leak, - water valves may fail or break, - plastic pipework may become distorted, - excessive evaporation may be lost from the water, - heating costs may be excessively high, - chemical consumption will usually increase, and microbiological activity will increase.
• The Maximum Heating Rate or Temperature Rise (or fall) for a concrete built pool is 1 deg C per 2 hours
• Big commercial concrete pools and similar structures will often have a maximum temperature rise (or fall) of 1 deg C per 4 hours
• Exceeding the maximum temperature rise can cause cracks, fractures and leaks in the pool structure due to unequal thermal expansion of the shell etc.
• Probably the worst shock for a pool shell is warm water being drained, and the pool immediately fast filled with cold water. This sort of action can cause terminal and often unrepairable damage to the structure.
• Although most liner type pools can enjoy a brisk temperature rise, most manufacturers of vinyl pool liners do not really recommend the water temperature to exceed about 29.4 deg C. If the recommended pool temperatures listed above are followed, this should not be a problem.
• High water temperatures can cause vinyl liners to expand and loose their elastic properties causing wrinkles and creases to appear which are usually impossible to remove. High temperatures can also destroy the oils and polymers in the material, so that the liner rapidly becomes brittle and susceptible to damage. Delamination of the various layers in the vinyl material construction also frequently occurs.
• Some manufactures do produce pool liners which are designed for higher temperatures. However, the manufacturers instructions and conditions must be closely adhered to if damage is to be avoided.