Best material to use in wet dry

[Hagenjames]

Right now I have crushed rock and cut up bio spong. What is best for a healthy tank ?

 

[cloak]

Being that the rock in your DT will be the primary biological filter, I think you would be better off keeping those compartments bare. Keeping things clean is definitely the name of the game in this hobby.. No need to clutter it up sometimes. GL.