I found a good pine bark fines source and bought 2 2 cu-ft bags to start with. I'll show a pic, but it looks more or less like the good pictures here on this forum, from dust to about 3/8" but a few slightly bigger pieces.

I mixed up some 5-1-1, and most of it is "curing" to let the lime do it's thing. However, I did pot up some that did not have lime in it, that I am going to plant blueberries in. That batch I watered to moisten up, and it seems that even with a fairly slow trickle, most of the peat seems to have "washed" down further into the pot. Is this a problem, and, can I prevent it?