Valken HPA and CO2 tanks do not come prefilled. Contact your local paintball or airsoft store or field for info on where to fill them.
HPA tanks can usually be filled at Paintball fields or stores and scuba shops. Call ahead and ask if they can fill a paintball HPA tank before going.
CO2 tanks can usually be filled at paintball fields or stores, stores like Walmart and Dicks that have a sporting goods section, welding supply stores, and any store that can fill kegerators tanks like beer supply stores and distributors. Call ahead and ask if they can fill a paintball CO2 tank before going