Answer

Best to use within a few days but will be useable for up to 2 weeks - perhaps even a month - before deteriorating too much. With time, there will be a depletion of the food source but also a build up of faecal and metabolic products. Keep either at room temperature or (preferably) in a fridge, removing a few hours before use. The culture includes flagellates as a source of food (Chilomonas, which is a flagellate protozoa). Loosen lid after receipt.