1ST LEAD Water in Rio pool being replaced in battle against green colour By Alexandra Mayer-Hohdahl, dpa

Rio de Janeiro (dpa) - Rio organizers are taking their battle against the unusual green colour that has plagued their open-air Olympic pools to the next level, with the water being changed Saturday in the basin where water polo competitions have been held.The strange colour of the two pools in the Maria Lenk aquatics centre, which is also used for diving and synchronized swimming events at the Rio Games, made headlines for days.Treatment problems have been blamed, 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 then complicated by rain."We‘re moving to a more radical approach with the water," Rio 2016 organizing committee spokesman Mario Andrada said Saturday.The process was underway by the afternoon in the water polo pool, after preliminary round competitions were held in the morning. The basin is also supposed to be used for synchronized swimming from Sunday.The adjoining diving pool, where competitions were underway on Saturday, is continuing to be treated with chemicals, venue media manager Simon Langford told dpa.Officials have insisted that the health of the athletes using the pools is not at risk.