I went too shallow on substrate and my cleanup crew died off
I learned a hard lesson recently. I set up a bioactive enclosure with what I thought was adequate substrate depth, maybe two inches over the drainage layer and within a few weeks my isopod and springtail populations were basically gone.
Turns out the heat from the overhead basking spot was drying out the top inch almost completely, which left the cleanup crew with barely an inch of usable habitat. Not enough moisture retention, not enough depth for them to retreat into cooler zones.
I tore it down and rebuilt with about four inches of substrate and the difference has been immediate. Population is recovering and the substrate actually holds a moisture gradient now.
What's the minimum depth people are running successfully? I clearly underestimated it.