In the amount of time that he didn't answer, I added some new inverts to my collection. Think I have enough for now! Was going to get them for myself as a Christmas gift but everything worked out. Still want them in the future!
I'm trying to get the 50/50 ratio right but keep adding more than the other. Now I think I have too much soil than sand! You can see the sand clearly when you clump the substrate though. What do you think?