A build material management system for an additive manufacturing system is described in which a recovered build material tank (208) and a mixing tank (212) are provided. The recovered build material tank (208) comprises an outlet and a first build material filter (218b) for separating a gas flow from a build material flow. The mixing tank (212) comprises a second build material filter (218c). The mixing tank (212) is connected to the recovered build material tank (208) via a RBMT-to-mixer conduit (286). A controller (295) is provided to couple the second build material filter (218c) to a reduced pressure interface to transport build material from the outlet of the recovered build material tank into the mixing tank (212) via the second build material filter (218b). The controller (295) controls coupling of the first build material filter (218b) to the reduced pressure interface to transport build material from a build material source into the recovered build material tank (208). A corresponding method is provided.