Specifically designed for Fluval Spec Desktop Aquariums, BIOMAX provides critical stage 3 biological filtration. BIOMAX's large surface area provides optimal colonization of beneficial bacteria, which enhance the elimination of fish wastes, resulting in a healthier aquarium environment.  Key Features:  Specifically designed for Fluval Spec Desktop Aquariums Provides critical stage 3 biological filtration Large surface area provides optimal colonization of beneficial bacteria Enhances the elimination of fish wastes, resulting in a healthier aquarium environment 60 g (2.1 oz)