Built this for a friend this evening.
I use a 20# tank stove like this in my shed, works like a charm.
So using a 30# tank should be fine, it would hold a "little" more wood.
I built one out of a 60 litre drum years ago - on the first lighting me and the dogs spent half an hour standing in the frost waiting for the shed to become cool enough to enter.
That thing was fierce!