I agree w/ danfrith.
If you're fortunate enough to select which organisms to drop into your 'fuge, here's what I'd suggest:
-copeods
-amphipods
-mysis shrimp
-some small bristleworms
-micro serpent or brittle stars
-chaeto or gracillira macroalgae
With the exception w/ the macroalgae, the above may/should come w/ your live rock and sand.
In my fuge I drop 2 cerinth snails for a week, every month. They help stir up the sand and crop microalgae.
I also have a few 1" x 2" x 2" coarse foam blocks wedged in a few places. I found that 'pods and micro stars like to use the matrix of holes for shelter and possibly munch on the detritus that could settle. Every once in a while, I'll move one into my display area to export some 'pods.