In a method embodiment, an example method includes attaching a balloon-filling apparatus to a water supply. The apparatus includes a fitting comprising an inlet and at least four outlets. The apparatus further includes at least four branch assemblies coupled to the fitting. Each branch assembly includes: a tube extending from the fitting at a respective one of the at least four outlets； a balloon comprising a neck disposed around an end of the tube； and a fastener attaching the neck of the balloon to the end of the tube and configured to automatically seal the balloon upon detachment of the balloon from the tube. The method further includes simultaneously providing water from the attached water supply to the balloons of the balloon-filling apparatus. The method also includes detaching one or more of the balloons of the balloon-filling apparatus using a force. The force is generated at least in part by one or more of: gravity of the balloons and the water contained therein； and an upward acceleration manually applied to the balloon-filling apparatus.
