Problem Solver - August 2007
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Keeping an Indoor Pool Clean and Healthy

We have an indoor pool that gets a lot of use, and we're looking for the best way to keep it clean and healthy.

If you don't pay close attention to the quality of your indoor pool's water and air, you will quickly hear from unhappy patrons, complaining about chlorine odor and eye irritation. Indoor pool and spa facilities can improve water and air quality through saline chlorination. Saline chlorinators have already enjoyed huge success worldwide. Now, that same technology has been developed to meet the specific requirements of commercial pools, providing an alternative to traditional commercial pool care and maintenance.

To find what suits your facility best, choose a company that's been treating aquatic facilities for many years and has experience in the recreational water market. Companies that stand out in the industry feature a complete line of industrial-quality NSF/UL-approved units with outputs ranging from 1.25 pounds per day to 25 pounds per day, specifically designed for commercial pool and spa applications. These units feature products and technology that automatically produce a consistent chlorine residual in the pool water while eliminating the shipping, storage and handling issues associated with calcium hypochlorite and bleach.

Your needs will vary depending on whether you need to retrofit into an existing pump room or incorporate the units into the design of a new swimming pool. For easy installation, look for units that are pre-mounted onto a backboard and can be mounted onto any wall surface in the pump room. Some systems that use bypass flow and are not in-line can be plumbed into any existing circulation system by tapping into the existing line.

For a commercial pool application, the criteria for the system you choose should include rugged industrial strength and the newest innovations available. All components used in the manufacturing of the systems should be industrial equipment and designed for round-the-clock operation. If necessary, the system should be able to operate at maximum output continuously. It helps if the power supply of the chlorinator is linked to the power supply of the circulation system, providing a safeguard to stop chlorination when the circulation system of the pool isn't operating.

Particularly easy to use, some self-cleaning units allow operators to simply use a dial—like a light dimmer—to increase or decrease chlorine production or combine with a controller for total automation. Some models also come equipped with an amperage meter and a low salt LED mounted on the front panel. These indicators make the operation even smoother.

Systems that feature a separate ORP input allow a regular controller to activate the saline chlorinators. This allows pools to keep existing controllers to maintain ORP and pH levels. Bathers will be able to tell the difference because the systems operate with as little as 0.5 percent salinity in the water. Compare that to seawater, which has a salinity of about 3.5 percent. The level of 0.5 is actually less than human tears and gives the water a pleasant, softer and silkier feel. In addition, swimmers experience less eye irritation, and there's less chlorine odor.

Such systems generally operate using the salinity in the water to produce hypochlorous acid. Because salt is constantly recycled during this process and available for conversion back to the active hypochlorous acid residual when it passes between the plates of the electrolytic cell, the only makeup required is when water is lost due to backwashing or splash-out.

BioLab, a Chemtura Company: