1. Fill each 2 liter amber mouse cage (actual capacity 2,750 ml) with 2 liters of system water.
2. Add approximately 30 seeds of boiled wheat, 1/2 tablet of brewer's yeast, and 1/5 of a Petri dish of paramecia seed culture.
3. Cover and stack the mouse cages and store in the light at approximately 28.5ºC.
The cultures will be ready to use in 4 days and will keep for about 3 weeks.