2ND LEAD Water in green Rio pool being replaced amid growing criticism By Alexandra Mayer-Hohdahl, dpa

Rio de Janeiro (dpa) - Rio organizers stepped up their battle against the unusual green colour that has plagued their open-air Olympic pools, as amusement over the problem turned into mounting criticism Saturday.

"Today was pretty gross. You‘re standing on the stairs and you can‘t see your feet, 1.5 metres down," Australian diver Maddison Keeney said after competing in the women‘s 3-metre springboard semi-final. "I just try to close my eyes and close my mouth."

German coach Lutz Buschkow called the conditions in the diving pool not "Olympics-worthy," questioning its cleanliness by noting that the water now also appeared to be coated in something. German divers had complained about a bad odour at the pool on Friday morning.

But organizers were focusing their efforts Saturday not on the diving pool, but on an adjacent basin - the main pool in the Maria Lenk aquatics centre.

Its water was being changed on Saturday afternoon, following water polo competitions in the morning and ahead of synchronized swimming events on Sunday.

"We‘re moving to a more radical approach with the water," Rio 2016 organizing committee spokesman Mario Andrada told journalists. "The water in the main pool will be replaced."

The diving pool is continuing to be treated with chemicals, venue media manager Simon Langford told dpa.

Treatment problems have been blamed for the unusual green colour, with FINA - the ruling body for water sports - saying that water tanks had run out of some chemicals, leading the pH level of the water to be outside the usual range.

Efforts to get the pools blue again were later complicated by rain.

Officials have insisted that the health of the athletes using the pools is not at risk.

Long-time coach Buschkow said he had never seen anything of the kind, pointing also to problems at the facility with cold showers and empty warm-up tubs.

"We repeatedly put pressure for the organizing committee to act to have dignified competitions here," he said. "I would like to see a faster change."