Feature Article - November 2006
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Special Supplement: Problem-Solver Guidebook

By Stacy St. Clair and Emily Tipping

Maintaining Water Balance in a Commercial Pool

Water quality isn't the first thing most aquatic directors think of when they talk about engaging patrons. But, really, is there anything less appealing for swimmers than a contaminated pool?

The right chemical balance can reduce contamination risks and let aquatic managers focus on other important operational matters. The best part? You don't need a degree in chemistry to make your pool safe and inviting for guests.

Q: Could my pool or spa be susceptible to contamination?

A: Absolutely. It's a scientific fact that commercial swimming pools and spas are breeding grounds for tough water conditions. These include both organic materials and inorganic materials introduced into the water by swimmers. Studies show that adult bathers will typically shed a layer of dead skin cells, a pint or more of perspiration, small amounts of urine and a few grams of oils and cosmetics into the pool.

Q: What should I do to combat contamination?

A: Your best hope is a water chlorination system that is designed to consistently and accurately deliver the chlorine you need to kill bacteria, control algae and destroy organic contaminants. The ideal system will leave your water clean, sparkling and sanitary day after day, all season long.

Q: Why are chlorine levels so hard to maintain on bright, sunny days?

A: First of all, you probably have more bathers on a sunny day than a cloudy one. More bathers, of course, equal more bather waste. That alone increases the chlorine demand.

But even without the extra bathers or high temperatures, sunlight can have a devastating impact on chlorine. Depending on other factors such as water depth and temperature, bright sunlight can destroy 75 percent of the chlorine in pool water in about an hour.

Q: How can I combat chlorine depletion on sunny days?

A: Add 25 ppm of cyanuric acid—known as stabilizer or conditioner—to the pool water. This should cut the chlorine loss by two-thirds.

Q: How does water temperature effect chlorine delivery?

A: Extremely cold water can slow down chlorine delivery for the same water flow through the chlorinator. To combat this, increase the water flow through the chlorinator. That normally does the trick.

Q: Why did my pool turn cloudy?

A: There could be several causes: a high pH, high total alkalinity, filtration problems or the need for shocking.

Double-check your recommended pH levels. Also verify that the filter is working properly and that the pump is properly circulating the water. If available chlorine levels are low or combined chlorine levels are high, a shocking of the pool water may be needed.

Q: What's that white stuff floating in the pool, and how can I prevent it?

A: It's probably small calcium carbonate particles that have enough trapped air to float. They can come from the natural insolubles in the product or be formed if pH or total alkalinity levels are too high. Operating the pump for longer periods should remove the residue through the skimmer. Check to see that the weir flap on the skimmer is functioning properly to prevent any skimmer residue from returning to the pool.

Q: How should I store my chemicals?

A: Chemicals, unless otherwise noted, should be stored in their original containers with sealed lids in a cool, dry, well-ventilated place. They should be kept away from heat, sparks, flames, direct sunlight and other sources of heat, including lighted tobacco products.

Because most pool chemicals are Class III oxidizers, local fire officials should be made aware of the storage conditions and the quantities you intend to store.


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