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

Key Points: Discuss water chemistry concerns for a spa or therapy pool. Emphasize that to
maintain proper water chemistry, circulation systems must operate 24 hours continuously. These
include:
Maintaining proper water balance. Hot water tends to play havoc with chemical levels.
As these levels fl uctuate, water frequently becomes unbalanced, making the water
conditions not only bad for the pool, but also bad for bathers.
Maintaining proper disinfectant levels. Because of the increased potential for
hazardous biological contamination, many regulations and standards allow for higher
disinfectant levels than in a pool. Chlorine levels as high as 10.0 mg/L are commonly
allowed.
Monitoring TDS levels. In the previous example where 6 people in a spa equaled 275
people in a pool, one can imagine how that affects the amount of chemicals that have
to be added to maintain proper water chemistry. Added to that, the bathers themselves
tend to excrete more bodily fl uids. All of this just adds to the TDS levels, requiring more
frequent draining and refi lling of the therapy pools and spas.
Key Points: Discuss the areas where codes and standards apply to spas and therapy pools.
These include:
Bather load restrictions. Many regulatory agencies set limits for how many people that
can be in a hot water vessel at a given time. This has traditionally been one bather for
every 3 square metres of surface area.
Water chemistry. As was mentioned previously, hot water creates numerous water
chemistry concerns. Often regulations require higher levels of disinfectant and more
frequent monitoring of those levels. Because of the frequent fl uctuation of other
chemical levels, it is often more diffi cult to maintain consistent water balance.
Circulation requirements. Because of the operational concerns mentioned earlier,
many regulatory agencies and standards call for much faster turnover rates than pools.
For example, therapy pools generally have a 3-4 hour turnover rate while spas have a
30-minute turnover rate. In addition, regulations require fl ow to not exceed the specifi ed
limits for drain covers to prevent entrapment.
Temperature. While temperatures for therapy pools are generally based more on
comfort than regulation, spas have a 40°C temperature maximum.
Health and safety. In many cases, other standards and regulations are in place to
safeguard health and safety. Some include circulation system requirements such as
anti-vortex drains, timers that shut off hydrotherapy pumps (making it necessary to leave
the spa to turn the system back on) and special signage that restricts usage.
Key Points: Discuss the types of people who might be at risk using hot water pools and spas.
These include:
Pregnant women
Elderly
Children
Individuals with heart disease
Individuals with high blood pressure
Individuals under the infl uence of drugs or alcohol
Users of prescription medication
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