The Bioscape Terra Base is a volcanic material that houses bacteria, allows drainage/water circulation, and has a mineral content. It is quite unique and can be used for the following.
Beneath plant soil in an aquarium to aid in allowing water to penetrate the layers.
Beneath more decorative gravel in an aquarium as above.
As a base drainage layer in terrariums - adding mineral benefit as plant roots reach it.
As part of a terrarium or reptile bio-active substrate "mix" - often terrarium substrates are mixes of coco peat, soil, sphagnum moss etc... Terra Base is a great addition to keep the mix "open" and of course add some mineral content.