My current meal worm farm has been running well so I thought I would share what I am doing.
I am still using the two drawer Sterelite with exhaust fan.
see: A better Meal Worm Farm
Meal Worm farm Exhaust fan
The beetle drawer has a thin layer of cornmeal substrate and lots of vertical paper egg cartons for beetles to climb and lay eggs onto. You have to keep moist food (carrot, potato) in here so they have a water source and sustenance. The beetles dont eat the cornmeal substrate but the newly hatched tiny worms will.
Perhaps every six weeks or so the baby worms will be of a size that it is time to move the farm forward. From the beetle drawer I dust off and remove all of the egg crates and then dump the entire contents into the worm drawer. The empty drawer gets cleaned and receives a new layer of cornmeal, the egg crates and every single beetle immediately picked out of the worm drawer as well as over the following weeks.
The substrate in the worm drawer keeps growing as you dump the eggs in every six weeks. After around 6 months it may be time to clean out the worm drawer. This is the annoying process involving sifting that nobody likes. But using this method, you only need to do it perhaps twice a year as the continuously added substrate keeps the worm drawer usable.
You do want to microwave your new layer of cornmeal for the cleaned out beetle drawer in order to kill off any chance of bugs. The beetles dont really need cornmeal so keep that layer thin so that it doesnt add much to the worm drawer each time. I personally feed both drawers with carrots, corn cobs, misc leafy leftovers such as lettuce, and on the worm drawer I will occasionally dump in leftover chicken bones with all of the unused meats, skin and fats left intact. The worms love this stuff and will eat the bones clean and then will also get inside and eat the marrow. Any cooked bones with marrow will be a welcome addition to your worm farm.
Dont forget to date your drawers. I use white board markers to do this as it washes off.