Why did the Olympics diving pool turn green?

It's not easy being green, whether you're Kermit the frog or an Olympics diving pool. On Tuesday, onlookers were shocked to see the formerly blue waters of the diving pool at the Maria Lenk Aquatic Center at the Rio Olympics turn a mysterious dark green. The water polo pool also turned a similar, sickening shade less than 24 hours later. Social media lit up with theories and expressions of confusion and disgust.

What caused this abrupt change?

According to FINA, the international governing body for the sport, some of the chemicals used in the water treatment process ran out, which allowed the pH level in the pool to drop. In a statement to the media, the Rio 2016 Local Organizing Committee explained that the green hue was the result of a proliferation of algae, fueled by heat and lack of wind.

The committee added that the water was tested and posed no threat to the athletes.

Rio spokesman Mario Andrada stressed during a press conference Wednesday that the pool's pH and chlorine levels were within the required standards and that both pools were treated during the night, with alkaline levels improving.

"The algae makes the water look green. We kept the same level of maintenance as we did before, but we had far more athletes," he said. "We had more dirt in the water and that generated more algae."

"If it were green and yellow, we would know it was a patriotic thing," Andrada joked, in reference to host nation Brazil's national colors.

But some athletes weren't laughing. On Wednesday, some complained that water treatments used to clear up the pools were impacting their events.

"I could barely open my eyes for the final quarter," USA men's water polo captain Tony Azevedo told journalists following his team's 6-3 victory over France. "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."

On social media, everyone from Olympians in Rio to people watching from home dived in with their take on the strange swamp-like Olympic pools.