Seachem Matrix is a high-capacity biomedia that provides housing for your nitrifying and denitrifying bacteria. Unlike conventional ceramics with limited external surface area, Matrix is made of natural material engineered with macro- and micro-porosity, giving you over 700 m²/L of colonizable surface area. That means: Ammonia → Nitrite → Nitrate → Nitrogen gas All in one media, inside your filter. Why it’s essential: - Supports aerobic nitrifiers on the surface - Supports anaerobic denitrifiers