You need to be a guest staying at that hotel to use the pool. Except for a few circumstances:
1. All guests of the All Stars resorts can use any of the All Stars pools.
2. All guests of Port Orleans Riverside and French Quarter may use the Port Orleans pools.
3. DVC members staying on points at a DVC resort may hop to other pools, except for AKL and any of the YC/BC/BCV pools, including the leisure pools, provided the period of time they are visiting is not blocked out AND they have requested permission to use the other resort pool.
If you would like to use a different pool from where you are staying, you are free to make a reservation at that hotel.