The most common type of worms for worm farms are Red Wriggler and Tiger worms. Both can be sourced from a hardware store or your local nursery. They come in bags of 500 to 1000, and they will multiply over time. It’s best not to purchase more than 2000, depending on the size of your worm farm.
If the rate your feeding the worm farm is faster than they can eat, it can create an acidic environment and they will suffer. If you notice the food is being eaten slowly, stop feeding them and wait till they finish.
Remember the worm farm needs to be kept moist. Some foods like fruit contain a lot of moisture, so keep that in mind when checking the soil.
If yours is the type of farm to capture liquid, empty this regularly. Its an amazing liquid fertiliser which should be diluted at least 10:1.