Tell me about the main swimming pools in Xining, their charges and opening hours.
There is a national fitness center in the International Village, 30 yuan, which is open all day. The price of Qinghai Hotel is 25 yuan, and it is all day. But changing water is not allowed on Tuesday afternoon. There is also a tropical rainforest opposite Wanjiajiaju, which is also open all day. I'm sorry for changing the water that day.