Abstract: Systems for containing and manipulating fluids including systems and methods involving supported collapsible bags that may be used as reactors for performing chemical, biochemical and/or biological reactions contained therein are provided. Generally, a series of improvements and features for fluid containment systems such as gas delivery configurations, foam control systems and bag molding methods and articles for supported collapsible bag vessels and bioreactors are provided. For instance, in one aspect, fluids contained in a vessel can be sparged, e.g., such that a fluid is directed into a container of the vessel, and in some cases, the sparging can be controlled by rapidly activating or altering the degree of sparging as needed. Multiple spargers may be used in some cases. In another aspect, the vessel includes a seamless collapsible bag. In some cases, the collapsible bag may be injected, blown, or spin cast molded.