I was having great luck burning Lauzon Cubex pellets this winter, then when I switched to the last pallet, I immediately started getting bad clinkers and blocked airflow needing daily (or more) cleaning. What was interesting (and of concern) is that the ash in the burn pot included odd specks of turquoise. I kept burning and reached out to Lauzon about what this could be, but haven't received a response. Does the community know what could be in pellets that would create this ash? A metal? Certainly hoping it's nothing harmful, but interested in any ideas.