Disclosure: My father-in-law maintains the pools at a local University.
This isn't like maintaining your above-ground backyard pool whereby you dump chemicals in by the bucket. These modern pools are computer controlled and have constant monitoring by the systems. As the system detects a change in PH or other imbalance, it automatically adjusts what chemicals are needed to be added. For 99% of maintenance it's about topping off the chemicals in the containers that the system draws from. These pools aren't that heavily used compared to those of a waterpark or other community pool which have hundreds (or thousands) of people in them on a given day.
Another example of how Rio screwed up.