I bought an EarthMachine one year ago and have been composting with worms laid on a concrete slab and while they are decomposing the waste, the process is super slow. Does anyone have tips to speed up the worms? They have plenty of waste to eat - there's probably 2,000 worms in the bin. The lowest layer is about 60% worm castings but they don't seem to want to move up into the rest of the pile. I have something to stir the pile and arate the bottom layer. I water the bin about once a week. I need help! I read reports that you can have usable compost in 2-4 months and I don't have anything in over a year.