Exo Terra Rain Forest Substrate 8.8L PT3117 | Tropical Vivarium Bark Mix

The ET Rain Forest Substrate (PT3117) is a natural, biodegradable terrarium substrate designed for humidity-dependent species — tropical reptiles, amphibians, and invertebrates that need a living, breathing floor layer to thrive. At 8.8L, it offers enough material to properly bed out a medium to large vivarium setup.

What's in the mix

This substrate combines sustainable Maritime Pine bark with natural Sphagnum moss. That pairing is deliberate — the bark provides structure and aeration, while the moss brings strong hygroscopic properties that actively draw in and hold moisture. The result is a mixture that functions as more than just a floor covering.

Humidity regulation

One of the key challenges in keeping tropical species is maintaining stable air humidity without creating stagnant, waterlogged conditions. This substrate absorbs moisture and releases it gradually, buffering humidity levels naturally over time. Consistent humidity supports healthy shedding and reduces the risk of respiratory problems associated with environments that are too dry or too erratic.

Planted terrarium compatibility

The particle size and shape of the bark component allow water to move through the substrate freely during irrigation, while still maintaining enough air pockets around root systems for healthy plant growth. If you're building a bioactive or planted tropical setup, this substrate supports both the living flora and the animals sharing the space.

Hygiene and safety

The substrate is heat-treated during production to reduce bacterial contamination before it reaches your vivarium. It is 100% natural and biodegradable, making it suitable for bioactive setups where substrate integrity and safety matter.

For keepers building tropical rainforest terrariums — whether for dart frogs, chameleons, crested geckos, or invertebrates — this substrate handles the foundational environmental work so you can focus on the detail of the setup.