Shanjing vivaria problem

Hi. I have made many setups to my newt based always in the same, black turf soil moss, moss, some fern and wood. But the newt with the time screws all the setup, the moss becomes many times dried out and I can´t stand looking to that mess. I have seen in the web some realy nice setups based on empiled Basalt rocks that gives such a nice looking to the vivaria and "reforce" the T.shanjing colouration what seems to be even better. I thought in doing that sonner I could, but I have read an article were they said that its unadvisable having the setup without some "soil" because it will have a very low average in Nitrifying bacteria witch will harm the animals has it appears... How can I make a rock-based setup without having a def. rate of Bacterial life forms?
Any sugestions for the setup?
The life of a shanjing, and also another caudata depend a lot in bacterial life has many may not