I'm ready to move my worm bed from a large plastic bin to something larger...and have at hand a cast iron bath tub. Anyone with experience using one? It is sheltered from direct sun but we do have many 90+ degree days here--and we have a few days each winter in the teens.

I guess my questions are 1) will I need to insulate this in some manner, and 2) will the tub, with its large surface area, provide adequate aeration or must I adapt it somehow?

The tub has high sides, so I put a 6" layer of small stone at the bottom for drainage, and another 6 inches or so of dirt on top of that before building the worm bedding itself, which is mainly leaves, soil, cardboard and previously frozen vegetable scraps. Composting is underway even without the worms on board. Depth of the composting area itself is maybe 8-12", about the same as the bin.

Thanks for any helpful experience with this sort of set-up.

SCinSC