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Here's Why the Olympic Pools Are Turning Green

If you've been on Twitter, you're likely aware of that time this week when the Olympic diving pool suspiciously turned from crystal blue to green... and then the water polo pool also mysteriously turned a murky shade of green the next day.

While the Internet offered many amusing explanations and memes, the FINA—the international governing body of swimming—has an explanation for the unusual water color. Apparently, the water tanks "ran out some of the chemicals used in the water treatment process." So, they just ran out of like, the one thing all swimming pool owners know to buy in bulk every summer. At the Olympics. Got it.

"As a result the pH level of the water was outside the usual range, causing the discoloration. The FINA Sport Medicine Committee conducted tests on the water quality and concluded that there was no risk to the health and safety of the athletes, and no reason for the competition to be affected."

Yet, the Rio organizers offered up other explanations, including a "proliferation of algae" caused by the lack of wind and a "sudden change in alkalinity", according to Mario Andrada, the communication director for the Rio local organizing committee. Whoever's actually at fault here, Andrada also emphasized that there is "absolutely no risk to the athletes or anybody."

One expert disagrees that the color is totally harmless. The missing 'chemicals' likely refer to a disinfectant, Ralph Riley, an expert from the London-based Pool Water Treatment Advisory Group, told USA Today. And since not enough disinfectant can be linked to certain health risks, Riley said his group strongly advised against swimming in green water.

While Rio organizers insisted that the "water will be blue from now on", (only time—and Twitter—will tell...) it seems like their attempts to hastily fix the problem with large amounts of chlorine have made things even worse. "I could barely open my eyes for the final quarter," Team USA men's water polo captain Tony Azevedo told reporters after their victory over France yesterday, according to the Washington Post. "This is the Olympic Games and they are putting so much chlorine in the water that people can't see. You can't have that." Another water polo player from Hungary agreed: "My eyes hurt from the water, it's not good." No, not good at all.

While the color itself is certainly distracting, it's clearly not priority no.1 for the athletes. "What's ridiculous is not the green water. I've played in plenty of pools with green water," Azevedo continued. "Who cares about the green water? The water could be any color, it doesn't matter. What matters is that it's safe for us."

Between health issues like Zika, toxic and sewage-filled water, and dangerous air pollution, it seems like Rio just can't catch a break.


Kylie Gilbert

Kylie is the associate editor for and She is a graduate of Northwestern University's Medill School of Journalism and Integrated Marketing Communications.

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