Exo Terra Bioactive Volcanic Substrate 2kg | PT3183 Vivarium Soil

The ET Bioactive Volcanic Substrate is a natural volcanic soil harvested from the mineral-rich foothills of the Aso Volcano in Japan. Formed from andesitic and rhyolitic tephra, it comes loaded with live beneficial bacteria and is designed specifically for bioactive planted terrariums — giving keepers a substrate that actively works to maintain a clean, self-sustaining vivarium ecosystem.

What Makes It Bioactive

The live Bacillus bacteria within the soil activate on contact with water or organic waste, breaking down biological material including leftover food and animal waste. This decomposition process eliminates ammonia and suppresses odours, keeping the terrarium environment healthier between maintenance. Active carbon is also included in the substrate composition alongside the natural volcanic soil.

Structure and Plant Performance

The substrate's porous, friable, low-density structure delivers excellent drainage and aeration throughout the root zone, directly supporting strong plant growth. Its mineral profile includes calcium, nitrogen, potassium, and phosphorus — nutrients that benefit both plant life and the microbial community. The absorbing properties of volcanic ash further help trap decomposed matter and eliminate odours over time.

Three Ways to Use It

• Sole substrate: Apply a layer of 2.5–5 cm deep. Bacteria activate with moisture or waste contact; rinse and partially replace every 12 months.
• Drainage layer: Use as a sub-layer beneath a biological top substrate such as plantation soil. Plant roots will extend down into the volcanic layer for enhanced growth. An inorganic drainage layer can be added below, with mesh separation, to prevent saturation and protect beneficial bacteria from being outcompeted by anaerobic species.
• Mixed into other substrates: Blends with organic substrates to enrich them with minerals, improve water retention, and introduce live microbiology to soils that lack it.

Ingredients

• Natural Volcanic Soil (Andisol)
• Active Carbon
• Live beneficial bacteria (Bacillus)

For keepers building a genuinely functional bioactive setup, this substrate does the heavy lifting at the foundation — managing waste biology, supporting plant root systems, and reducing the frequency of full substrate changes.