Just add helium to the balloons and enjoy. Inflate balloons same day of event. Latex balloons have an average indoor float time of 12-24 hours. Foil balloons can last multiple days if filled and stored properly. Balloons used outdoors will have a much less float time due to the elements. Foil balloons require a low pressure regulated foil inflator to inflate them. These regulators have an auto shut off pressure valve and will not over inflate them. Disposable helium tanks with a latex inflator will not properly inflate foils. Balloons can usually be properly filled at your local party supply store florist and even some larger grocery chains will offer helium. For larger balloons or larger quantities of balloons it may be more cost effective to rent a helium tank from a party rental company or local welding supplier.