How to make a Terrarium in 4 steps … The size of your container will affect the amount of materials you will need and use: 1. The first layer is rocks, which you can purchase at pet, garden or craft stores. Add enough to the bottom for adequate drainage. 2. The next layer is activated charcoal, which you can get at pet or garden stores (it is used in fish tanks). Add a thin layer over the rocks. 3. Depending on the depth of your container, you will next add soil. Leave enough ...
