Direct Info from Product Website : https://fluvalaquatics.com/us/product/bio-stratum-8-8-lb-4-kg/

Made from 100% natural, mineral-rich volcanic soil from Mount Aso in Japan and infused with beneficial nitrifying bacteria, Bio-Stratum is specifically formulated to provide immediate biological activity and maintain ideal conditions for a thriving planted aquarium. Characterized by its non-compacting 1 mm powder granules, Bio-Stratum allows plants with even the finest and most delicate roots to easily spread throughout the porous substrate while absorbing a powerful mix of nutrients, minerals and trace elements that promote explosive growth and overall health.

• Promotes healthy plant development, vigorous growth and vibrant color
• Infused with dormant beneficial nitrifying bacteria that, once in contact with water, are activated to break down waste and kickstart the nitrogen cycle
• Rapidly reduces ammonia levels to help stabilize water conditions in new aquariums
• Lightweight 1 mm powder format granules are non-compacting and allow even the finest and most delicate roots to easily penetrate and spread throughout substrate
• Porous granules promote extensive bacterial colonization and act as an additional source of biological filtration for improved water quality
• Includes a powerful mix of plant-friendly nutrients, minerals and trace elements
• Helps support a neutral to slightly acidic pH – ideal for live plants as well as tropical fish and shrimp commonly kept in planted aquariums
• Softens water naturally, reducing carbonate hardness
• Will not stain water and helps control organic discoloration
• Unique curing and heat treatment process helps extend soil life and ensures no parasites are present
• Ideal for use in smaller freshwater aquariums or as a top layer in larger tanks