Actually, there are hours of operation noted at each of the pools on the signs near the pools and hot tubs. So they technically are not open 24 hours a day. But if you are quiet, you probably can swim past the closing time.
I did find an Keynotes (OKW newsletter) that stated pool hours were 10AM to 10PM.
Slides are closed once the lifeguards are gone for the day. That means no slides when they are gone for the day.