Zoo Med’s NEW Tropical Bioblend is the perfect substrate for your Tropical Bioactive Terrarium. Let’s break down what’s in it: The ReptiSoil™ base combines humus, peat moss, sand and carbon to provide a living space for your “Clean-Up-Crew” to thrive in while also providing nutrients to your plants. Also added to this substrate blend is ReptiBark®. These small chips of Fir Tree bark provide drainage and aeration for the soil and prevents compaction making sure that your invertebrates can move about the substrate. Lastly, Sphagnum Moss is added to retain moisture and boost the humidity of your tropical terrarium. Sphagnum moss will also resist decay making this substrate long lasting. Available Size: 8 Dry Quarts