Highest porosity and largest useable surface area, per unit weight or volume, of all filtration media available anywhere. For use in all soft or hard freshwater or brackish aquariums. May also be used in marine systems. Provides huge amounts of aerobic and anaerobic surface area for efficient bacterial colonization. When properly colonized, and used as directed, it will reduce toxic ammonia and nitrites to near zero in all marine aquariums. Also reduces phosphate significantly and dissolved organics. Works excellently as the only filtration medium for the aquarium or pond or may be employed in addition to other filtration media. For use in all soft or hard freshwater or brackish aquariums; may also be used in marine systems When properly colonized, it will reduce toxic ammonia and nitrites to near zero in all freshwater aquariums Provides huge amounts of aerobic and anaerobic surface area for efficient bacterial colonization; One 1. 5” block has about 4,000 square feet of useable surface area Reduces phosphate significantly and dissolved organics Works excellently as the only filtration medium for the aquarium or may be employed in addition to other filtration media UPC 810086012954 Item Form Block Brand Name Brightwell Aquatics Unit Count 4 Count Item Weight 0.12 Kilograms Manufacturer Brightwell Aquatics Model Number FXPBLOCKBIO1.5in-4pk Item Type Name Aquarium Filter Media Target Species Fish Included Components FW Xport BIO Blocks Allergen Information Sulphites Free Manufacturer Part Number FXPBLOCKBIO1.5in-4pk