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Why Pool Water Turns Green and Other Common Pool and Spa Water Quality Issues


quality pool and spa

During the 2016 Summer Olympics in Rio de Janeiro the swimming pools turned dark green. It turned out that a facility employee had accidentally dumped 160 liters of hydrogen peroxide into the pools, which canceled out the effects of chlorine, thereby supporting the growth of algae and other organic compounds.

“Of course it’s an embarrassment,” an Olympics spokesman said at the time. “We are hosting the Olympic Games. We should have been better [at] fixing it quickly. We learned painful lessons the hard way.”

To get the water quality of one of the pools back to where it needed to be for a synchronized swimming event, officials decided to drain and replace more than 3.7 million liters of water. Not only did this water quality issue slightly tarnish the Olympics, it also resulted in a lot of waste.

In the pool and spa industry, monitoring water quality is a top priority. Pool and spa owners monitor water quality to maintain safe swimming conditions, keep swimmers satisfied, and protect the pools and spas themselves.

Common water quality issues in the pool and spa industry

When water chemistry falls out of balance, pools and spas can experience these three common problems.

1. Dirty-looking water

Would you jump into a pool that looked dirty? When pools and spas aren’t maintained properly, water can look cloudy, murky, and discolored—which isn’t exactly inviting for a swim.

2. Too much chlorine

Chlorine is a critical ingredient in many healthy pools that helps kill bacteria and algae so the water looks clean and appealing. However, too much chlorine increases acidity, which can damage the swimming experience. For optimal conditions, pool water pH should stay within the 7.2 to 7.8 range.

3. Hard water

When calcium and magnesium levels are too high in your pool or spa, hard water is created, causing water to look cloudy or milky, with high pH levels.

What happens when water quality issues are not addressed?

When water composition is out of balance, problems arise. At one end of the spectrum, water may simply look dirty or discolored. At the other end, the water can be irritating for swimmers—and even damage the pool or spa itself.

Here are three common things you may experience when water quality issues are not addressed.

1. Bad aesthetics

As the Olympics example illustrates, when chemicals in a pool or spa are out of balance, the water can start to look funky. Whether you operate a country club, a public pool, or a water park—or you have a pool in your backyard—maintaining proper water characteristics conveys an alluring aesthetic. Even if water that appears green is safe to swim in, many people will probably decide against getting wet.

2. Irritating water

Water that has too much chlorine in it can irritate the eyes, skin, and lungs. Chlorine makes water more acidic; improper balances can corrode piping, pool equipment, and certain pool surfaces (i.e., concrete). That said, chlorine is an essential ingredient in clean pools. Without it, bacteria growth can accelerate.

3. Damaged pool and spa surfaces and hardware

When hard water persists, your pool or spa can be damaged by white residue left behind on walls, ladders, and other surfaces. As a result, the value of your assets decreases and the swimmer experience is diminished.

How to ensure quality pool and spa water

Water quality monitoring equipment is used to ensure pool and spa water characteristics stay within optimal ranges. These tools can help pool and spa owners continuously monitor pH, alkalinity, oxidation reduction potential, free and combined chlorine, temperature, and more.

In the past, employees would have to monitor quality manually. Thanks to modern water quality monitoring instruments, however, they can leverage Bluetooth technology to keep track of various characteristics on any connected device. For example, portable pH meters and testers can help you monitor pH levels with confidence, sharing data and running analytics on an as-needed basis.

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