Looking at a space heater and the manual says to use k1 kerosene, not farm fuel. Any one know the difference between k1 kerosene and #1 diesel fuel? Keep getting mixed results when looking. Some sources claim #1diesel is k1. Best description I have found is k1 is supposed to be low sulfur for use in heaters. Found a listing of 400 ppm for k1, seems high when compared to ulsd at 15 ppm.