mwp blend. 25f here at the moment. mostly light (weight. not color) fly ash. i've taken to just brushing it away from the edges of the pot till i vacuum at the end of the week. the pan takes forever to fill with the heavier stuff. i've got two tons of the mwp softies waiting for when it's 20 below. ($235/ton) but the blends handled that fine for me last year. i'll know by the end of the season if buying the softies is worth it for me or not.