Rio Olympic organizers have changed the green water in the main pool at the Maria Lenk stadium ahead of synchronised swimming Sunday but divers are not going to receive fresh water of their own.
An unusual green colour has plagued the open-air Olympic pools for days and has attracted criticism and complaints.
"We changed the water of the synchronised swimming pool, the big pool," Rio 2016 organizing committee spokesman Mario Andrada said Sunday. He said the process took around 11 hours of work.
Synchronised swimming requires athletes to see each other to coordinate moves which could have been difficult in the murky green water. Competition started at 11 am (1400 GMT).
Water polo also took place in the Maria Lenk stadium but can now move, as planned, the Aquatics Stadium after the swimming events concluded Saturday.
Andrade said scheduling meant the water in the diving tank would not be changed but it "is getting better by the hour."
The women's 3-metre springboard final is at 4 pm.
FINA - the ruling body for water sports - believes the water colour changed from blue to green as water tanks had run out of some chemicals, leading the pH level of the water to be outside the usual range.
Officials have insisted throughout the health of the athletes using the pools is not at risk.