Rio Olympics 2016: Why did the Olympic pool turn green?
THE water in the Olympic diving pool turned from blue to bright green last night, but it was not wee that did it.
The shock change in colour caused widespread puzzlement among divers and audiences as the women's 10 metre platform final progressed in Rio – but the experts have stressed that it is "crazy" urine would have turned it green.
Brett Blair, a national manager of Jim's Pool Care, said when asked by the Guardian in Sydney.
"It’s a very curious one, because the main reason a pool normally goes green is lack of sanitation."
Blair said that there was a possibility that the pool's filtration system may not have been able to handle a pool of that size.
He said that is "way too big" for the colour change to be caused by urine.
"It's way too big. My gut feeling is that it will be cleared up over the next 24 to 48 hours."
The centre plays host to the diving and waterpolo events.
Britain's Tom Daley tweeted "Ermmm... what happened?!", alongside a picture of the green-coloured pool in the Maria Lenk Aquatics Centre, which contrasted sharply against the still-blue colour of another pool beside it.
The pool appeared blue during the men's 10 metre platform event on Monday, in which Daley won a bronze medal alongside teammate Daniel Goodfellow.
More from the Olympics
Tonia Couch, who finished fifth alongside Lois Toulson in the women's 10m synchro, said: "I've never dived in anything like it. We noticed it in the warm-up and then by the competition it was even more green."
Unsurprisingly, Twitter went into meltdown last night with some interesting theories guessing exactly why.
Unconfirmed reports claimed that the pH level in the pool had risen to 9, an alkaline reading, when the optimum level is 7.4, much closer to neutral.
That would indicate there was not enough chlorine in the water, which in turn could have allowed green-coloured algae to grow.
A statement from the organisers read: "It's very important to the Rio 2016 community to ensure a high quality of play. Tests were conducted and the water was found to be safe. We're investigating what the cause was."