Hi, Hibiscus flowers only last a single day and they are gone so that is not unusual. Hibiscus are very sensitive to the soil drying our and if it does the plant will loose leaves, drop flower buds and turn yellow. make sure the soil stays uniformly moist. Not too sure what yo mean by the "inner pot". If the plant is in a small pot then all the more reason for maintaining uniform soil moisture. They also like to be fertilized about every two weeks or so with an liquid type fertlizer.