On Tuesday, the Maria Lenk Aquatics Centre's diving pool turned green. Yesterday, the water polo pool followed suit. Various reasons have been, er, floated, depending on who is doing the blaming, I mean explaining:
• It's a change in alkalinity, says Mario Andrada of the Rio 2016 local organizing committee. "We expect the color to be back to blue soon," he said. "…There is absolutely no risk to the athletes or anybody."
• No, actually heat and still air caused an algae bloom, according to the Olympic organizing committee.
• More likely, says FINA, the International Swimming Federation, is that the water tanks "ran out some of the chemicals used in the water treatment process."