Exo Terra Sub Stratum Bioactive Volcanic Terrarium Substrate

Exo Terra

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The Exo Terra Sub Stratum is collected from the mineral-rich foothills of the Aso Volcano in Japan. The natural volcanic soil, formed from andesitic and rhyolitic tephra, is very nutrient rich, ideal for lush plant growth in bioactive planted terrariums.  The porous surface allows for excellent drainage and aeration, supporting strong root growth. The Sub Stratum’s friable, low density structure promotes a flourishing population of beneficial, nitrifying bacteria, creating a self-sustaining, living terrarium ecosystem. The active beneficial bacteria of the soil will decompose biological waste, keeping the terrarium clean and healthy.

Bioactive Volcanic Substrate

  • Natural bioactive soil
  • With live beneficial bacteria
  • Stimulates plant growth
  • Keeps the terrarium clean & healthy
  • Eliminates ammonia & odors
  • Great drainage capabilities
  • Ideal for bioactive planted terrariums
Exo Terra  BFA Item #
Sub Stratum 4.4 lb. (2 kg) EX23183
Sub Stratum 8.8 lb. (4 kg) EX23184


The secret to growing healthy plants begins with the soil. Naturally, healthy soil contains living microorganisms — from bacteria to fungi, protozoa and arthropods. Together they form a choreographed exchange from the recycling of nutrients to the decomposition of organic materials.

By mixing the Sub Stratum with other organic substrates, you enrich any substrate with the required minerals like calcium, nitrogen, potassium and phosphorus. It also aids in the water retention capacity and provide adequate air supply to the roots.

Only use R/O water or tap water treated with Aquatize in bioactive planted terrariums to remove heavy metals, chlorine, and chloramines.

The regular use of Turtle Clean to add extra beneficial organisms to the terrarium water will support the biological filtration capabilities.

Ingredients: Natural Volcanic Soil (Andisol), Active Carbon, Live beneficial bacteria (Bacillus)

"Nothing is lost, everything is transformed" - Antoine de Lavoisier

Made in Japan

Sub Stratum – Bioactive Volcanic Substrate – 2 kg / 4.4 lb
Sub Stratum – Bioactive Volcanic Substrate – 4 kg / 8.8 lb