Amazon Basin Gravel ( ABG ) is a substrate mix specifically designed for terrariums and aquariums, inspired by the natural conditions of tropical rainforests. It is typically composed of several elements, such as:
 Sphagnum : A moss that helps retain moisture and maintain a humid environment.
 Bark and Hulls : Provide natural elements for drainage and support.
 Soil : Adds nutrients for plants and promotes the development of a healthy ecosystem.
 Gravel : Aids drainage, preventing the accumulation of stagnant water.
 ABG substrate is valued for its ability to support plant growth, retain moisture, and create a natural environment for reptiles and amphibians in terrariums.