jmann - Welcome to
Talking Reef!
I have crushed coral in my tank and I use the typical clean up crew - blue legged hermits, astrea/turbo snails, cleaner shrimp. I believe the crushed coral can be a problem for livestock that burrow or sift sand (such as certain gobies and sea stars).
Typically when I do my water changes, I just siphon a portion of the substrate to keep it clean. Seems to work just fine...the key is water changes, to not over stock the tank and good water movement. If you keep your
nitrates and
phosphates in check, then you can keep your clean up crew pretty basic.
As IReefIKeeper mentioned, if you have a 30 gallon tank then you really should return the tang to the
LFS.
Jason