Xport Freshwater BIO Brick

For use in all soft or hard freshwater or brackish aquariums; may also be used in marine systems  When properly colonized, and used as directed, 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  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 9" x 4.5" x 2.5" Brick. Made in the USA