Pond Matrix, 20 L / 5.3 gal. High capacity biofiltration aquatic plant substrate High porosity product designed to provide exceptionally efficient biofiltration Removes ammonia, nitrate, and nitrite from decorative ponds thereby promoting a healthy environment for both fish and aquatic plants Also serves as clean soil replacement allowing the culture of aquatic plants without the use of muddy soils 1 Liter treats 100 US gallons