Feature Article - July 2012
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Wet Your Whistle

Improving Aquatic Safety and Aquatic Management

By Kelli Ra Anderson


Water clarity has been and remains an ongoing issue for operators as a result of the differing standards and regulations around the country. But whether the water is drinking-water clear at .5 NTUs or allowed by some agencies to max at 1.0 NTUs (relatively clear but usually must be returned to .5 NTUs within one turnover), a more practical standard prevails.

Since the recent passage of the Virginia Graeme Baker Pool and Spa Safety Act in 2007 by President Bush, (a law intended to ensure that drain covers are properly installed and maintained to prevent entrapment), the law dictates that the main drain or bottom drain of any pool must be clearly visible (preferably down to its screws and manufacturing label) from the pool deck at all times. Any cloudiness, fogginess or doubt about haze demands the immediate evacuation of any pool.

"Clearly, operators don't want that to happen, particularly during a prime swim time," Arko said. "The advantage of being able to operate—having healthy patrons and revenue—means that if you have to shut down during a summer season, you are losing hours of time. Obviously, that's not a good situation."

According to Arko, water can go from clear to cloudy within minutes. With the sudden addition of a large birthday party into a pool, for example, if insufficient chemicals (clarifiers and oxidizers to help the filter do its job more effectively) are being added, water clarity can change very quickly, requiring everyone get out and the pool to be shut down until clarity is restored.

The key solution to preventing this problem is to ensure that the operator and the equipment (read: the filter) are top rate. Operators should be certified.

"I would highlight that anybody who has anything to do with a pool should be certified and have gone through a commercial pool operating class to understand all those things," Arko said about a job that requires constant evaluation. "It's a matter of diligence. They're in the business of getting patrons in there and members paying and the worst thing that can happen to them is to have accidents happen and people saying it isn't safe. There may be extra maintenance involved, like the addition of clarifier or oxidizing the water more regularly, but if you look at the long term, the resulting damage from not doing this far outweighs the cost."

Don't Bug Me

Water clarity is primarily a function of filtration, but chemistry is also required to protect equipment and especially to protect the swimmer from pathogens like Cryptosporidium and Giardia. To that end, having an operator who understands the vital importance of regulating the pH in the water and to have a system sized to meet the bather load, is yet another reason to make sure you've got the right staff in the right place.

"You've got the sanitizer, like chlorine, and pH, and between those, pH is far more important," explained Mark Caldwell, general manager of Pool Services Corp., who teaches and licenses out of state pool operators from his business in Myrtle Beach, S.C. "It controls the effectiveness of the sanitizers you're using. It is the number one detractor in the ability of sanitizer to do its job because high pH takes the H off the acid and you get a hydroxyl, which has absolute zero killing power."

In his native South Carolina, regulated pH levels have been lowered to 7.0 to ensure the more effective aggressiveness of hydrochloric acid (e.g., at 8.0, only 25 percent of the acid in the pool is actually working to kill harmful bacteria).

However, regulating pH isn't the only challenge. Having a system properly sized to meet bather load demand is another problem far more common than most realize. "The builder puts in pools set by the state specs, but it has nothing to do with demand. Until you open the pool, you don't know what kind of demand you're going to have, and you have to modify the chemistry delivery system in order to do that," said Caldwell who suggested that a properly managed and calibrated chemical delivery system can keep water clear and avert the need for shocking a pool even at maximum capacity by maintaining breakpoint chlorination. "It takes equipment, automation and a pro."

However, sometimes less is more. Caldwell has helped many pools cut down on needless energy costs from using flow rates that are higher than most pools need—especially during their closed seasons—by using variable frequency drives. "This has been very cost-effective on pump motors of 10 horsepower and greater, with payback periods of 12 to 24 months," Caldwell said. "The same principals apply to smaller pump motors, but the payback period is generally three to four years."