I’m going to use a 4 tier plastic drawer set as used by others. These are easily sourced and cheap. I’ll try to keep a running total of cost which I’ll update later. The drawers will be in an insulated box. This will have a heat source and ventilation. I’d also like to have some form of humidity control but haven’t come across a solution yet. A few people have said that the moisture source for the mealworms (eg carrot) provides sufficient humidity, so I’ll see how we go. I’m going to use the Arduino platform to control the farm as I’ve messed about with it for some time and this will give me an excuse to mess some more.