Just a reminder for those that leave powder in the hopper......
Get a small label, about 2 or 3 inches long (1/2 x 2 in) and with a good pencil or Permanent ink, write the full name of the powder in the hopper and put this label inside the hopper on top of the powder. If you add powder to the hopper, raise the label to the top again. If you do this you will "never forget" what powder is in the hopper.