Soaking in water is a common first step, particularly for seeds with a hard or aged shell. The seeds are dropped into a glass of room-temperature water and left for twelve to twenty-four hours until they sink or show a small white tip. Instructions on how to germinate autoflower seeds generally warn against soaking for longer than a day, since the embryo needs oxygen and can drown. After the soak, the seeds go into a damp towel or straight into the growing medium.