With good water, few fish, and time you will start to see life. When I first started, I didn't see anything for a couple of weeks. One night I shined a flashlight into it and was amazed at all the little critters.That was 8 months ago. It's been 3 months since I've added any new rock, and a couple of weeks ago I found a new critter.
Don't know what kind he is or if he's bad, but I guess time will tell.
Just be patient and you'll find critters too.