Final answer:
There is no specific wait time mentioned. Once the free chlorine level reaches the desired range, patrons can enter the pool immediately.
Step-by-step explanation:
To raise the free chlorine level in the pool quickly, liquid chlorine needs to be added by hand. However, there is no specific wait time mentioned in the question. Chlorine levels need to be tested periodically to ensure they are within the safe range of 1-3 ppm. Once the free chlorine level reaches the desired range, patrons can enter the pool immediately.