Thanks, Fighter, I think I'll make me a rake. An underwater Zen sand garden.
I knew substrate in general could get those pockets I just didn't realize I had to stir the sand so often. Ooooops, I feel bad, my ignorance just killed two perfectly good cories. >_<
I think I may use playbox sand this time, too. That aquarium stuff is so fine and almost powdery. As long as I don't use rough sand the cories should be okay. I put a huge pot over the one area in the tank where I can see the sand turning black, don't want them digging around there.