Here's a bad picture of mine. Heated room in my unfinished basement. Looks like a dungeon lol. Has a window though. Probably about 6x8'. I have a space heater on the ground set at about 72 in the summer and 68 during the winter(to keep electric costs down). Since warm air rises I put my cooler kept insects on the floor and the roaches up higher where it gets to the 80s.
To keep from having to brave the dungeon every morning to feed the chams, I keep a feeder bin of different staple roaches upstairs in the cham room where I load it with high quality dry gutload, fresh veggies, and thawed blended wet cubes of everything. This is nice because I can gutload more precisely. I buy big bags of organic carrots and oranges to feed all the colonies downstairs. It keeps them reproducing and alive while I save money on the expensive gutload only using a little in my feeder bin.
