Xport Freshwater BIO Block - 2 Inch

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 2” block has about 10,000 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  Made in the USA