i just throw the new lump on top of the old, and sort of mix it around a little bit with the ash tool.

This morning I pulled all the old out, because there were lots of little (hole blocking size) pieces in there. I put the biggest new pieces on the bottom, then the medium sized ones, then I put the old, mostly little ones, on the top. Sure helps keep the holes in the grate free to draw air.

Also I noticed that although I always re-use the un-burnt lump, it never really burns as good as it did when it was new, so I try to watch what per cent of each I use.

I usually fill up to 3/4 of the fire ring and use the old lump until it gets to about 1 inch of the top air holes in the pit. I do quickly stir the old lump go get the small pieces through the bottom grate. I will get from 3 to 5 cooks until I add more fresh lump, I don't bother mixing used with new.

If I think I need some new lump I put it in. No mix just cook. If I am going to do a long cook I will then push the old lump to one side and put fresh at the bottom, then move the old from the other side on top of the new. Put some new in and slide some old over ontop of the second side.

Really it isn't something I worry about too much. I have not had any problems with temps low or high.

Possibly it is a case of beig fat, dump and happy.

I just keep adding more and scoop out the bulk of ashes through vent. Save $$ on charcoal with minimal effort.