The answer depends on one question. What do you plan on doing with the weed once it's been vaped?

If you plan on cooking with it, then you'll want to try to save some THC as well as most of the cannaboids, seeing as how they aren't vaporized when you smoke out of the volcano.

If this is your objective, then start on a moderate setting of 5. After taking a bag, turn it up to 6 and hit it again.

If you aren't trying to save any "re-fried" weed as some say, then simply turn it up to 7 and let er' rip. I'd even recommend taking another pass at 7.5 when yer done.

An interesting thing to note: When vaporizing weed, everything that's left over is already "activated"--meaning that you don't need to heat it up and dissolve it into butter/ethanol before cooking with it. You could theoretically just dump a fat pile into any cooking recipe and have at it. It makes cooking with cannabis much easier.

Anyways, hope that helps.