Zebra mussels (Dreissena polymorpha) with a shell length >1 mm are adaptable to laboratory conditions if ammonia levels are low (<1 mg/L) and water temperatures range between 4 and 24 degrees C. The most difficult aspect of maintaining mussels is providing acceptable food that will support growth and survival over a long period of time. Several standard invertebrate foods, such as yeast, bacterial infusions, and live and dried algae were tested for initial acceptance and long-term survival. The mussels accepted and survived best on green algae (either live Chlamydomonas reinhardtii or dried Chlorella sp.). A ration of 3.2 g of algae (dry weight) per 1000 mussels (shell length>10 mm) resulted in an average growth rate of 2 mm/month.