Both 1680 and BLK are fine grained.
BLK seems to be a bit worse.
Racist! I get that schit EVERYWHERE!
I keep a small paint brush I picked up at Walmart for a $1 or less quite a while ago..
it hangs on a cheap hook, I screwed into the side of the RL Bench..
It takes care of that powder mess, into a dust pan...and I throw it on brown spots on the lawn..
makes a nice fertilizer, and greens up those brown spots...
The wife appreciates that... myself... I don't get all that concerned about Brown Spots in the grass...
that is what women care about turning green.....m wife wants a wonderful green lawn and stuff like that to impress the neighbors..
but then doesn't do lawn work at all....she thinks that is what a husband is for.. that and fixing her car..