Bio Drain goes at the very bottom of the terrarium, underneath the soil — it is a drainage layer, not a bedding you keep an animal on. Water that runs down through the substrate collects in the gaps between the porous granules instead of standing in the root zone, which is what stops a planted terrarium going sour and anaerobic. That makes it a bioactive and paludarium product. If you keep an arid species on dry sand with no misting and no live plants, you do not need a drainage layer at all, and this is not the bag to buy.
One size, 2kg (4.4 lb). Spread it across the terrarium floor, lay a mesh separator over the top if you want to stop soil washing down into it, then add planting substrate above. It is inert and non-decomposable, so it stays put for the life of the build and can be rinsed and reused, and it is designed to run alongside an isopod and springtail clean-up crew. For a humid floor without a bioactive build see the Forest Moss Mat, and the rest of the range is in our Exo Terra collection.
Features
- Bottom drainage layer — sits directly on the terrarium floor, below the soil, never on the surface.
- Porous structure — the granules host beneficial bacteria that break down biological waste, so the layer acts as a biological filter as well as a sump.
- Prevents waterlogging — excess water drains clear of the roots, avoiding the anaerobic conditions that make a planted terrarium smell.
- Will not rot — inert and non-decomposable, unlike bark or coir layers that collapse over a season.
- Clean-up crew compatible — intended for bioactive builds running isopods and springtails.
Specifications
2kg (4.4 lb) per bag, item code PT3115. Shipping weight 2.055kg. Exo Terra does not publish a granule size or a coverage area for this pack, so we have left both out rather than estimate — layer depth is set by the build, not by the bag.