I have a 2006 Quadra Fire Castile insert and I burn Pack Saddle wood pellets which are suppose to be the cleanest burning pellets on the market. Just curious what setting on the control box do I set for these pellets? the range is 1 to 5. Currently I have it set on 4 and notice lots of sparks flying from the burn pot which looks nice but it leaves ash. Everything works fine, just want to be efficient.