The only reason I've used cc instead of some other substrate is because our water is on a softer side, cc buffers it up and keeps it stable without the need for chemical buffers.
As an alternative though (if your water is soft and needs buffering) you could have pool filter sand as your substrate and use some cc in your filter as media.
Sand has a tendency to sink, not keeping the cc mixed in (it'll eventually just come to the top of the sand), what you can do is either use the aragonite sand or mix it with pool filter sand to have a more uniform look.