I got the mung beans from a health food store. Probably other beans, or lentils could also be sprouted and eaten, but my experience is limited.
One person I knew years ago supported himself with two hours of labor a day by raising alfalfa sprouts in jars. The jars were in a rack in his closet. It was sort of like an assembly line. New jars got started every day and the oldest sprouts got packaged in baggies and sold to local markets.
I make wire cradles with handles to suspend the jars in the air with hooks from a pipe. The original pickle jar lids are modified to hold stainless screen which holds the sprouts in while letting them drain off excess water.
It takes about a week to go from seed to ready-to-eat sprouts, moistening the sprouts two or three times a day.
Step 1: Cutting the Lid Ring
The nibbler is a tool I don't use much, but for this kind of job it does a very good job. It takes baby bites of the material every time you squeeze the handles.
I got my nibbler many years ago, possibly from Home Depot.
The wire screen circle gets held to the top of the jar by this ring.
I have a little stainless steel screen material that was given to me years ago by a museum staff friend of my mother's. It is not a common material and I am not sure where I would get more today. I don't live in a big city, and that is probably a specialty item. A Google search for stainless steel screens will result in some possible Internet sources.
Without stainless steel screen, I would probably substitute cheese cloth or mosquito netting for it. A layer of cheese cloth might be held by the lid ring. If not, the cheese cloth might be held with rubber bands or string, instead of the lid ring.
I would avoid possibly toxic materials such as aluminum screen. I consider aluminum to be possibly toxic because of some associations with Alzheimer's disease and levels of aluminum. My preference is to not cook with aluminum pots. Others may feel more comfortable with the idea of using aluminum for the screen, but I'm just a little cautious.