MICROPOND is a minimalized ecosystem for investigation of effects of long-term-microgravity on ciliates. The only inhabitants are Stylonychia mytilus and Chlorogonium elongatum. The MICROPOND was automatically controlled by a computerprogram. The longest lasting experiment was stable for 48 days. The pH-value was about pH6.8. The oxygen concentration varies between 70% and 100% air saturation. The temperature was about 22°C.