Beth,
Its funny how that happens. I thought my sand was devoid of life for quite some time, after adding a few batches of sand from a few people (we're talking handfuls here) and "patiently" (read impatiently
) waiting, my sandbed is full of life! Its great! Here I thought I would never be able to say I had all sorts of critters thriving in my sandbed but here I am. It took awhile though for them to get to a population that I could actually see. Seriously, try adding the fresh sand first and then just add a bit of the good stuff. Chances are if there isn't all that much sand in there to begin with, your critters are hanging out in the rock and will come out when you add more sand (just an idea).
Good luck
Christy
