What about the water in my pool? Is it safe?

Experienced swimming pool owners know that there is rarely one chemical that can treat and prevent all problems in an optimum manner. For this reason, a combination of chemicals/ treatments is often used. The trick is to use combinations that will provide clean, clear, and pleasant pool water to minimize harmful side effects, and, at the same time, to customize your pool water treatment to meet your specific needs.

Water Care Requirements.

Maintaining excellent water quality should be a priority for all pool owners. No matter which water treatment is selected, the following are always required:

  • Sanitation (or disinfection), the killing of bacteria and viruses
  • Oxidation, the elimination of non-living material (anything excluding bacteria and viruses)
  • Residual, retaining some sanitizer in the water at all times

Any water treatment unable to meet all three requirements, whether it is one or a combination of chemicals, will not be fully effective in meeting your pool water basics and ensuring that the water is clean and safe.


The most common sanitizer is chlorine, which is excellent in killing bacteria and viruses. In fact, it is used to fulfill all three water care requirements, whether it is introduced directly or it is produced from salt via a chlorine generator. Although clearly well suited to über-athletes, according to the Aquatic Exercise Association, "The water's unique properties" provide an environment for people of all abilities. Buoyancy creates a reduced impact exercise alternative that is easy on the joints..."

In fact, the Arthritis Foundation reports that the swim spa's environment of warmth and buoyancy makes it a safe, ideal setting for relieving arthritis pain and stiffness. It recommends water exercise as a gentle way to exercise joints and muscles. Note that in an outdoor pool, the sun destroys much of the chlorine. Of the chlorine that remains, more than half is used up for the removal of non-living waste, such as grease, oil, cosmetics, sun tan lotion residue, urine, and sweat. Biguanide is the favorite of many, not only because of its functionality as a sanitizer but also because it produces a silky-smooth feel in the water.

In addition, using a biguanide means that you will avoid the "chemical smell" that is associated with chlorine. Bromine is acknowledged as an effective sanitizer, but it is better suited for indoor pools or for outdoor pools in northern climates where there is less sunlight exposure (because, like chlorine, it is not stable in the sun). Unlike chlorine, however, there is no stabilizer to protect bromine from the sun's rays. Silver is used in mineral product containers or dispensed from an automatic ionizer. Since there is still some uncertainty with respect to how well and how quickly bacteria are killed by silver, it is recommended that some chlorine be used in combination with the silver. Bromine is not compatible with silver; therefore, the two cannot be used in combination.


Chlorine reacts with and becomes incorporated into waste, such as urine or perspiration, forming very unpleasant-smelling chemicals called chloramines, which are also called combined chlorine. These chloramines are responsible for eye and skin irritations and for the characteristic "chlorine smell" in and around pools. As the chloramines form, more chlorine must be added, a process known as super chlorination or shocking, to "burn out" contaminants in the water and to continue the killing of bacteria and viruses.

To prevent these problems, many pool owners prefer to use a separate and more efficient oxidizer. Monopersulfate is a stronger oxidizer than chlorine. Monopersulfate is normally added on a weekly basis. It is odorless, is not degraded by the sun and has a minimal effect on pH and pool water chemistry. When bromine is used as a sanitizer, it also acts as an oxidizer, but it is not as strong as chlorine. As a result, separate oxidizers or shocks are commonly used in pools treated with bromine. Hydrogen peroxide is the oxidizer used with biguanides since chlorine and bromine are not compatible with biguanides. Hydrogen peroxide has a minimal effect on pH. Ozone, fed into the water continuously by an ozone generator, is the strongest oxidizer for pool water treatment.

Ozone has a minimal effect on pH and water chemistry. Both monopersulfates and ozone are compatible with chlorine and bromine.


Some sanitizers should always be in the water to kill or inactivate bacteria and viruses. The presence of the sanitizer as a residual helps ensure that when bacteria or viruses are introduced to the water from bathers or the environment, they are inactivated and exposure to people is minimized. Chlorine, bromine, and biguanides all meet this requirement since they stay in the water for some time. There are test kits available for the pool owner to test and ensure that the sanitizer is present. Real Choices for Real Gains Pool owners have a variety of choices available to meet their water care needs. By using specialized products, or by combining products, consumers can achieve the key pluses without the troublesome minuses.

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