I can tell by the Easter egg green water that what happened is the water has copper in it, and the PH was abruptly raised followed by a chlorine shock. Not algae.
Happened exactly that way to mine several times to mine.
I’ll bet they mistook the copper problem for an algae problem. Then they did a hydrogen peroxide shock to kill the algae. All of this is probably done by a local pool maintenance contractor who doesn’t know what he’s doing. He’s then giving half baked explanations to the olympic organizers who are passing them along with their own added misinterpretations. The media is of course clueless and just prints what they’re being told without really understanding or questioning it.