[Will work for bbq]

I think using the 18" charcoal ring works great for a naturally aspirated burn but not so good with a fan. I tried it with my Guru and Stubbs charcoal for the first time and it took forever to get up to 275* and every time the guru cycled off the temp dropped ~15-20*. Once I figured it had to be the 18" ring I removed it and the temp spiked then settled and was rock solid. I haven't tried going to 300*. But make sure the vent with the fan adapter is open, that happened once on my 18" the vent worked its way closed and I wasn't getting any airflow.