The combination of FlowCon and AerationSystem has been designed to enable the users to process shake flasks cultivations in non-humidified and non-CO2-controlled incubator shakers. The FlowCon provides a controlled gas composition and flow rate. Simultaneously, the AerationSystem (consisting of GasDivider and AerationCaps) humidifies and distributes the gas flow to the connected shake flasks to prevent evaporation losses and stabilizes the pH of the media. The control of gas compositions was designed for a variety of different applications, including stem cell processes that require physiological oxygen concentration or anaerobic cultivations in a nitrogen atmosphere.