A drainage layer within your terrarium means that you can keep a layer of water at the bottom of the enclosure, which then keeps the humidity up and ensures that the above layer of soil is kept hydrated. This is particularly important if you’re keeping live plants or using a bioactive custodian set up.

To create this, simply use a layer of ProRep Bio Life Medium on the bottom of the enclosure, ideally around 1-2″ thick, then place a layer of hydro matting neatly over the top of this, which prevents the soil from leaking down into the drainage layer. Then place your chosen substrate on the top, and water gently, filling at least half of the depth of Bio Life Medium.