About half have died off as expected. I think they are sticking to the mesh lining of the breeder box so next time around no putting wigglers in there. I am using this quartz silica sand my local hardware store sells for like $8 for 100lb bag.
Great stuff, Chris! keep us updated. I had a few of those breeder boxes over the years and I found I would lose fry by them getting caught between the frame and the net.