Originally Posted by smokey void
from what i've seen and have been told it's best to use nat coals, i guess because of the heat distribution, since the hole in the phunnel is in the middle and close to the top, no matter where you set the coal you're gonna have heat directly over the hole, where as w/nat coals the heat is dispersed more evenly, idk it's just the logic that runs through my mind, i have no complaints w/my new vortex as of yet except i'm out of nat coals and will have to wait to get more since the hookah shop here in town only carries qls, and like i said i will be getting a phunnel next, just a matter of when
You can use QL coals, naturals are just better in all regards. If all you have is QL just break them in half and arrange them around the edges if you are worried about the heat being drawn down the center. There should be no holes over the spire so that shouldn't be a problem. Or you could use 33mm coals which are smaller than their 40mm brothers.
The reasons that many of us are such supporters of natural charcoal include better flavor, less chemicals we don't know about, less CO and better burning properties. These advantages mean that some people have a tendency to shout about using naturals over QL without actually giving an explanation. This is probably where you got that idea. QL coals will work on a funnel they are just not ideal because they are inferior coals.