The STB-1400 is not suitable for long-term culture, as it requires daily replenishment of culture fluid. We recommend using our stretching systems suitable for long-term culture. Additionally, check that the lid of the system is put on during the experiment. Placing a 35 mm or 60 mm dish with water at any location within stretching system will slow the evaporation of culture fluid. The velocity of evaporation of culture fluid heavily depends on the condition of the incubator. Check the condition of evaporation dishes, and confirm that sufficient coolant is in the plastic container attached with the stretching system and it circulates properly. If you do not have any problems with the above and still have the evaporation problem, try to put cotton wool with purified water nearby the chamber of the stretching system.