High capacity biofiltration
Controls ammonia, nitrite, and nitrate
Highly porous – enormous surface area (>~700 m2/L)
Supports aerobic and anaerobic bacteria species
Use 250 mL of Matrix for each 200 L (50 US gallons) of water.

EHEIM LAV consists of volcanic rock and is a natural product.
Its rough, highly porous surface structure provides the purification bacteria with very good colonisation conditions.